When Does Implantation Bleeding Occur
Implantation bleeding is the mild uterine bleeding that occurs
when the zygote(fertilized egg) is
getting buried or implanted in the lining of the uterus. The bleeding occurs at the end of the process of implantation.
The Timing of Implantation Bleeding
The bleeding from implantation usually occurs about 10 to 14
days after fertilization, which is about the time of your ovulation day. This
is usually at the end of the implantation process. Note that
implantation bleeding does not
start at the beginning of
implantation, but at its very
If your cycle is the textbook 28 day average, then your ovulation day is about Day 14 of your cycle. If you are unsure about how to predict your ovulation day, please read When Am I Ovulating?
The Timing of Implantation
After fertilization, the egg moves towards the uterus and enters the
uterine cavity after about 2 to 3 days. Once in the uterine cavity, the process
of implantation starts about 3 to 4 days later and last a total of about 4 to 5 days. That means implantation starts about 6 to 7 days
after fertilization and lasts about 3 to 5 days.
The term implantation window is the medical term used for
the period of time that the uterus is best prepared to receive the fertilized
egg for implantation. This is usually from day 20 to day 24 of an average 28
Is It Implantation Bleeding?
Before asking “when does implantation bleeding occur?”, it is important to be sure you are dealing with implantation bleeding in the first place.
I would suggest you review Is This mplantation Bleeding to ensure you do not mislabel an abnormal uterine bleeding as implantation bleeding when it is not.
Leveno KJ, Hauth JC, Rouse DJ,
Spong CY. Chapter 3. Implantation, Embryogenesis, and Placental
Development. In: Leveno KJ, Hauth JC, Rouse DJ, Spong CY, eds. Williams Obstetrics. 23rd ed. New York: McGraw-Hill; 2010. http://www.accessmedicine.com/content.aspx?aID=6030341. Accessed January 1, 2014.