Implantation Bleeding

When a tiny spot of blood appears on the underwear of someone trying to conceive, suspicion immediately arises: is this implantation bleeding? Is it finally my time to become a mom? However, unfortunately, not every bleeding is a sign that a baby is on the way.

We should remember other possibilities, including menstruation. In fact, usually these light bleedings occur due to the onset of menstruation, which may start “dripping” before it begins in full.

So, how can you tell the difference between implantation bleeding and an approaching menstruation? Normally, menstruation has a heavier flow, but when the flow is lighter and scantier it can cause confusion. In this case, it is best to wait a few days and see what happens before getting your hopes up. Even a minimal flow should always be considered menstruation initially¹.

Implantation Is the Exception, Not the Rule

Implantation bleeding is the exception, not the rule. We can say that only 20% of women experience this bleeding after implantation. And not all women who get pregnant are able to see it. It is not common to confirm pregnancy through implantation, since the bleeding is of very low volume².

Implantation bleeding happens due to the embryo attaching itself and shedding of the endometrium. To explain better: imagine the uterus as a cushioned field where the baby will settle, and for that to happen, the “cushion” needs to be opened.

This settling into the cushioned field causes a small amount of blood in the endometrium and, if it finds a way out, this blood will exit through the woman’s vagina. However, implantation bleeding is without flow and lasts only a short period of time.

How Many Days Does Implantation Bleeding Last?

We can say that implantation bleeding should not last more than 3 days and should not have any flow. If it does, something could be wrong. In such cases, there could, for example, be a hormonal deficiency (progesterone), which would put the recent pregnancy at risk. If you notice anything like this, see a doctor.

Implantation Bleeding – Characteristics

But how do I know if the bleeding I had was really implantation? How do you distinguish it from breakthrough bleeding? Simple: implantation bleeding is the pregnancy bleeding. And only with the presence of HCG in the body can you be 100% sure that it was implantation.

In addition, to suspect implantation, the blood should not have any volume at all. Another specific characteristic is its color: light red or brownish red. It can also appear as a spot or just brown discharge, but always in very small amount.

Breakthrough Bleeding Due to Medication Withdrawal

Remember, not all blood is implantation bleeding; it can have many other causes, including breakthrough bleeding in some cases. In addition, some women may experience bleeding due to the use of medications such as the birth control pill or the morning-after pill, for example.

These are cases of breakthrough bleeding due to medication withdrawal or as a reaction. If you don’t want to get pregnant, there is no need to panic. However, if a few days pass and your period still doesn’t come, it’s a good idea to take a test just in case.

How Long After Implantation Bleeding Can I Take a Test?

Only after the embryo implants is the pregnancy hormone HCG produced. Before this, there may be only traces of it in your body.

That’s why, if the test is done too early, the chances of getting an indeterminate beta HCG result are very high. This happens with the quantitative test, since the qualitative test doesn’t even detect such low levels. In general, we can say that the quantitative beta HCG can be done from the 5th day after implantation or possible implantation bleeding, but always within a period of 7 to 15 days after the sexual intercourse.

Implantation Bleeding

Some pharmacy pregnancy tests can detect HCG on the 2nd day after implantation. The most sensitive ones, which detect at least 10mUi, may show a very faint line, which can be confusing. In case of doubt, it is recommended to repeat the test in 48 hours, a reasonable period for the HCG to double in quantity. If the bleeding does not stop, it is advisable to see a doctor.

Readers’ Questions:

How do you tell apart implantation bleeding and menstruation?

The difference between implantation bleeding and menstruation is in the amount and volume of blood. Implantation is minimal, just enough to stain the underwear, and stops quickly. Menstrual bleeding will increase over the days and tends to last longer.

How does implantation work?

Implantation is the embryo attaching to the uterus³. After the fertilization of the egg in the fallopian tubes, it travels to the endometrium where it will attach and become a baby. It is during this attachment in the uterus that implantation bleeding can occur.

Is implantation with twins different?

No, it is impossible to determine the number of babies based on the symptoms of implantation. The signs are identical to those of a single pregnancy.

I had sex during my fertile period and there was bleeding. Could it be implantation?

No, because it’s still too early for implantation to have occurred. What can happen is, if a woman bleeds after sex, it may indicate a sore on the cervix that, after penetration, caused some breakthrough bleeding. Implantation bleeding at this stage is not very common. It is important to note that if you have a positive pregnancy test and then start bleeding, this could indicate a threatened miscarriage. You should see your doctor to find out whether it is just implantation bleeding, a miscarriage, or even an ectopic pregnancy. Also see: Can White Discharge Be a Sign of Pregnancy? How to Identify?