Implantation bleeding and spotting happens within 1-2 days after arrival of the blastocyst in the uterus, usually around 9 days after ovulation (dpo), with a range of 6-12 days. At that time, the blastocyst is barely visible to the naked eye, probably smaller than the dot above the letter "i". Once it happens the blastocyst becomes the "embryo".
On Which Day Does Implantation Happen?
The attachement of the embryo to the uterine wall usually happens within 1-2 days after the embryo has arrived in the uterus, about 5-7 days after ovulation and fertilization, on average, 9 days after ovulation and fertilization, with a range between 6 and 12 days.
Is It Implantation Bleeding or a Menstrual Cycle?
Pregnancy related bleeding usually presents about a week before your menstrual cycle is due to begin (or a week after ovulation). Many women refer to this as spotting or do not even notice the bleeding at all.
It is important to understand that the blood associated with implantation bleeding is not going to be fresh blood. The time it takes for these drops to move out of the body ages the blood. It will appear dark brown, even black by the time the spotting occurs.
Is Implantation Bleeding Common?
The bleeding or spotting is a result of the egg implanting in the endometrial lining of the uterus. It happens in most pregnancies, but not every woman notices the blood. Between 20 and 30% of women have spotting associated with the early changes of pregnancy but this spotting is not the same as pregnancy bleeding in most cases.
There is no complete agreement among experts whether it can be felt or not. Some women claim they can feel implantation while many pregnant women did not have any symptoms at that time.
Implantation and the bleeding usually happen about a week after ovulation and fertilization when the fertilized egg which immediately after fertilization is called the "zygote" and then becomes the "blastocyst" or "blastula" arrives in the uterus.
- Attachment of a fertilized egg ("blastocyst") to the lining of the uterus
- The process of attachment of the embryo to the endometrial lining of the uterine wall
- The process that occurs when the embryo burrows into the endometrium and eventually connects to the mother's circulatory system
- The bedding of the embryo into the lining of the womb
- The process where an embryo embeds in the uterine lining
- Signs include:
- Cramps: small cramps inside the uterus
- Spotting or bleeding: Short brief spotting (a couple of drops of light or dark blood)
- A second temperature shift on the temperature curve
- A temperature dip at about seven to ten days after ovulation
Most women have no subjective symptoms at the time of implantation, no bleeding or cramps, but some women report some drops of blood, while others report small cramps.
These symptoms can happen with or without conception and pregnancy and of these symptoms and these chart patterns frequently occur on charts that do not result in pregnancy.
These signs are thus quite unreliable for early pregnancy detection, though they can offer some clues. Similarly, some women have typical early pregnancy symptoms while others don't have typical symptoms.