Pregnancy brings with it many strange and unfamiliar symptoms.
But one of the most terrifying – or completely unnoticed symptoms if you have irregular periods – is implantation bleeding.
We know what you’re thinking: “Here we go again!
Yet another mysterious vaginal fluid threatening to stain the sizzlin’ new thong I got from Victoria Secret!”
But here’s some good news: implantation bleeding doesn’t always occur.
In fact, only close to one-third of all expecting mothers experience it, and it may not happen with every pregnancy.
Table Of Contents
- 1 Please, Tell Me More About This Delightful Pregnancy Symptom
- 2 Implantation Calculator
- 4 What Happens During Implantation?
- 5 Step 1: The Apposition
- 6 Step 2: The Adhesion
- 7 Step 3: The Invasion
- 8 Hold Up – Is This The Same For Moms Who’ve Had IVF Treatments?
- 9 What About ICI And IUI?
- 10 So When Does The Bleeding Happen?
- 11 And It Lasts How Long?
- 12 And Cramping Happens When?
- 13 And My Temperature Does What?
- 14 The Colors Of A Demented Rainbow In Your Underwear
- 15 What About The White Stuff?
- 16 What Is This “Late Implantation” Business?
- 17 The Later The Implantation, The Less Viable The Pregnancy
- 18 Can I Eat My Way To A Better Implantation Rate?
- 19 I’m Sure It’s Implantation Bleeding But The Preggo Test Reads “Negative”?
- 20 Light Bleeding During Pregnancy: Not A Reason To Freak Out
Please, Tell Me More About This Delightful Pregnancy Symptom
Before we dive right into what implantation bleeding is, let’s take it back a bit to a couple of days after you and your partner got busy in the bedroom.
Once the champion sperm has successfully fertilized your egg (which can take up to 72 hours), the blastocyst (a.k.a. your baby up until it becomes known as an “embryo” after implantation and until the eighth week of gestation at which time your bubs will be referred to as a “fetus”) begins to rapidly divide and grow.
Your smart growing baby will also be sending out signals telling your body to get ready ‘cuz it’s about to get a new roommate.
One of the signals is telling your uterus to make thicker walls (also known as the endometrium), perhaps partially for soundproofing but primarily so that your uterus will be able to protect and nourish the blastocyst/embryo/fetus over the next nine months or so.
Our implantation calculator estimates your implantation date, whether you’re trying naturally or having fertility treatment.
Disclaimer: Every pregnancy is different so the dates given are approximate. You must not rely on this calculator as a substitute for medical diagnosis or advice from a healthcare professional.
What Happens During Implantation?
Six to twelve days after fertilization, that fast-growing embryo has moved right on down the Fallopian tubes to the uterus, and then THIS happens:
Step 1: The Apposition
Apposition is the very first phase of the attachment process.
At this point, the blastocyst (a ball of cells that will become your baby) has sought out a small crypt (think of it as small curvy dent) in the endometrium, possible because these crypts, being curved, increase the area of contact with the otherwise kind of round blastocyst.
The blastocyst will try to align itself so that the area with the least amount of “zona pellucida” (think of this as the “outer shell” for your egg) can connect with the uterine wall in order to establish contact with the underlying trophoblast (the stuff that provides nutrients to your embryo and will transform into a large part of the placenta later on) and the decidua (the lining of your uterus) of the endometrium.
Phew, that was a lot of thumbing through the dictionary!
At this point, the connection between the blastocyst and the endometrium is pretty loosey-goosey and is not well secured.
Step 2: The Adhesion
At this point, your embryo and uterus are jiving well and have a much stronger attachment.
Your embryo and endometrium are communicating at breakneck speeds with your embryo essentially bossing your uterus around and telling it to make more room.
Step 3: The Invasion
The embryo is pretty established in the endometrium at this point.
Trophoblast cells continue to penetrate your uterus, secreting hormones and stuff which helps it to further wiggle its way in there.
Decidual cells blocking the way are knocked out of the way.
Your immune system typically rejects and destroys cells which are different from that of the mother. But your brilliant little embryo secretes immunosuppressive agents which allow it to fly right under your immune system’s radar.
Hold Up – Is This The Same For Moms Who’ve Had IVF Treatments?
Women who have had IVF treatments have just as much of a chance of having implantation bleeding than those who have become pregnant naturally.
Here are some general timelines for when you may want to throw down a pantyliner to protect your ginch:
Implantation after an IVF cycle will occur anywhere from 6 to 10 days after the retrieval of the egg
…which will be 1 to 5 days after the blastocyst transfer
…which is the equivalent to day 20 to 24 of your natural menstrual cycle (assuming you have a 28-day cycle)
A study from 2012 found that the implantation rates for those who have had IVF treatments are nearing those of natural conception.
As with a natural pregnancy, the younger a mother is, the more likely it is that the embryo will successfully stick themselves to the wall of your uterus:
- Under 35 Years: 37.1% success rate
- 35 to 37 Years: 27.5% success rate
- 38 to 40 Years: 18.3% success rate
- 41 to 42 Years: 9.7% success rate
- 43 to 44 Years: 4.1% success rate
- Over 44 Years: 2.2% success rate
No real surprise there.
But in case you were wondering, the clock is tickin’ away for both IVF and naturally pregnant ladies.
What About ICI And IUI?
Both types use a catheter or some other medical device to insert sperm into the uterus.
The primary difference is that with ICI the sperm is “unwashed” and with an IUI, the sperm is “prewashed”.
The prewashing gives sperm a better chance of reaching those magical fallopian tubes (that’s where the magic happens, folks!) as the pregnancy rate for IUI is 15 to 20% per cycle (the odds can be anywhere from just under 6% to over 26%).
IUI isn’t too far behind, however, with a success rate of 10 to 15% per menstrual cycle.
Implantation after an IUI and for an ICI can take place within 6 to 12 days if both artificial insemination techniques were well-timed.
Ovulation and Implantation: How to Get Pregnant Fast (Even with Infertility)
So When Does The Bleeding Happen?
The reason why implantation bleeding occurs is that your aggressive embryo has disrupted the tiny blood vessels in the spot it chooses to attach to, which may result in bleeding.
This bleeding will usually make itself apparent anywhere from 10 to 14 days after ovulation and after your egg has been fertilized.
And It Lasts How Long?
Implantation is nothing like your period which takes days to exhaust itself.
It’s more like spotting and will only last for a day or two. Some women may only have one quick bout where she will notice a wee dab of pink or brown stuff in her underwear or on her toilet paper after a wipe.
And Cramping Happens When?
Not all women experience cramping during the implantation process (haven’t we suffered enough?!).
But some will feel light cramping (we’re not talking period-style heavy duty cramps here), twinges or twangs while it’s going on.
If you aren’t as “tuned in” to your body as some other moms out there, you’ll likely think it’s just gas.
And My Temperature Does What?
If you were keeping track of your temperature over the past several weeks or months to track your ovulation, keep doing it afterward.
One of the signs of successful implantation are regular temperature fluctuations for a week to a week and a half after ovulation (if you were keeping track, you’ll definitely see what we’re talking about here).
The Colors Of A Demented Rainbow In Your Underwear
Implantation bleeding is often mistaken for being yet another anticipated visit from Aunt Flo because it occurs somewhat around the same time you would expect your period.
But unlike your period which is often a rusty rouge to eventually a bold and blazing red (and sometimes fraught with clots), implantation bleeding is smooth and will feature an array of Crayola browns and/or pink-toned discharge because it is old blood.
Also unlike your raging period, it’ll stay light and will not increase in quantity or duration.
If you didn’t grab the pantyliner like we suggested, your loss (R.I.P. undies).
What About The White Stuff?
The seldom spoken about “white discharge” which we women often deal with on the daily can also be a sign that you are pregnant – or that now is “go time” because you’re ovulating.
Women who have thick white discharge while pregnant (though you may not even know it yet) will have an increase in this stuff in order to keep your cervix healthy and ironclad.
It’s yet another sign of early pregnancy you may experience.
Having a thick white discharge before your period may also be a sign that you are ovulating (if it is soon enough) or it just happens before, and sometimes after, your period.
It’s normal, so sit down – you’re cool.
When you may not be cool is if your discharge is:
- Clumpy (think cottage cheese clumpy)
- Accompanied by a strong odor
- Accompanied by itching
In these situations, it’s time to give your doctor a call.
What Is This “Late Implantation” Business?
Just to screw with your already stressed and worried mind more, there is something which is known as “late” or “delayed” implantation.
This can occur after both natural conception and fertility treatment.
When your embryo actually implants will differ from mom to mom and pregnancy to pregnancy.
In a natural pregnancy, your embryo has anywhere from 6 to 10 days after ovulation (the average is 7.1 days) to bust out of its shell and get to work.
Late implantation is considered to be anywhere from 8 to 10 days after ovulation.
For those undergoing fertility treatments, after a day 5 blastocyst transfer, that group of cells should start to implant within 1 to 2 days.
There isn’t a whole lot of leeway after this amount of time for your embryo to implant itself.
After your estrogen starts to rise and the progesterone hormone kicks in, the clock starts ticking for when the uterine lining will be receptive, and when it will not.
While it isn’t exactly known what causes late implantation, one study found a number of associated factors, including:
- When you started your period (in this case, a “late menarche” or “late period” resulted in an increased occurrence of late implantation)
image source: ImplantationBleed
The Later The Implantation, The Less Viable The Pregnancy
The New England Journal of Medicine published a study which found that the later it takes for the blastocyst to implant itself, the more likely you will miscarry or that the pregnancy will not be successful.
- On the 9th day, the miscarriage rate was 13%
- On the 10th day, the miscarriage rate jumps to 26%
- On the 11th day, the miscarriage rate doubles to 52%
After day 11, the risk of miscarriage increases rises to 82%.
Can I Eat My Way To A Better Implantation Rate?
This is a load of BS.
Perform any search on the web and you will likely find ridiculous articles claiming that pineapple, bananas, tofu, green tea, raspberry leaves and other foods will increase your chances of implantation.
There is no hard scientific evidence which proves that any of these foods will help increase your implantation rate.
Know what will?
Which will be prescribed.
By a professional.
I’m Sure It’s Implantation Bleeding But The Preggo Test Reads “Negative”?
Keep in mind that implantation bleeding is one of the earliest signs of pregnancy.
It often happens before you have confirmed that yes, your period has been missed (“missed” is a strong word for that…) and occurs prior to you suffering through morning sickness, sore boobies and the other common symptoms of pregnancy.
Before you worry about not being pregnant or curse the dollar store pregnancy test you bought (no shame there), remember that pregnancy tests are designed to read positive only after a certain level of a hormone known as the human chorionic gonadotropin hormone (or hCG from here on out – I’m not typing that again) is high enough to be detected in your pee.
When implantation bleeding occurs, your hCG levels are often so low that not even the most advanced test will be able to tell you that you are expecting.
Yes, you’re excited and you just need to know whether or not you are with child.
But even if you have a test in hand which claims to be able to tell you that you’re preggers 3 to 4 days before your missed period, retake it after you are sure your period has been missed.
If it’s still reading negative, pay a visit to your doctor and he or she will likely arrange for you to have a blood test to confirm your pregnancy.
Within a week or two of your missed period, that pregnancy test will be pretty darn reliable.
Light Bleeding During Pregnancy: Not A Reason To Freak Out
Light bleeding during pregnancy, whether it is during the implantation phase or any other stage, is normal.
If you and your partner were particularly rowdy in the bedroom or if you had a pelvic exam recently, you may also experience light bleeding.
So put down the phone.
It’s probably close to midnight and your doc is fast asleep.
The best thing any pregnant mama can do is kick up her feet and relax.
Throw on a ridiculous Rom-Com with Ryan (pick your favorite: Reynolds or Gosling), eat some ice cream, and wait until the doctor’s office opens at 9 am to make an appointment.
No matter what is in the cards for you, everything is going to be fine.