Every healthy woman experience monthly bleeding. This monthly cycle is called menstrual cycle. The duration of menstrual cycle varies woman to woman but the average duration of menstrual cycle is 28 days. In this article we will consider a woman having a menstrual cycle of 28 days. After every 28 days woman starts bleeding vaginally. The duration of this bleeding also varies form 3 – 7 days. If the bleeding stops in one or two days or continue more than 7 days than it couldn’t be menstrual bleeding and other causes of vaginal bleeding must be excluded and you you should see a doctor to have a proper physical and vaginal examination.
There is another medical term called “implantation bleeding”. This bleeding occurs at the start of pregnancy and indicates attachment of embryo to the wall of uterus. Actually embryo embed itself in the wall of uterus and encroaches the uterine wall. During this encroachment the uterine vessels rupture and appear as vaginal bleeding. This bleeding occurs near the same time of expected menstrual period and a woman think that she has got her period. The following image shows implanted embryo. You can notice easily that the newly formed embryo embed itself inside the wall of uterus.
How to know whether it is an implantation bleeding or menstrual bleeding?
The main thing which differentiate implantation bleeding from menstrual bleeding is history, duration of bleeding, consistency and flow.
If woman has the history of unprotected sex with her partner and she is not on any kind of contraception and she is expecting a pregnancy and bleeding occurs around the days when her menstrual period normally starts then she shouldn’t think that this is menstrual bleeding this can be implantation bleeding.
Now another differentiating point between menstrual and implantation bleeding is duration of bleeding. Menstrual bleeding continues for at least three days but the duration of implantation bleeding is less than three days. If a woman who had unprotected sex and expecting a pregnancy but she experienced bleeding afterwards and the duration of bleeding is lesser than 3 days (or equal to three days, but usually not more than 3 days) , then it could be implantation bleeding which indicates start of pregnancy.
Menstrual bleeding contains necrosed debris of previously hypertrophied uterine wall and it is thicker in consistency and darker in color while the implantation bleeding is lighter in color and thinner in consistency as compared to menstrual bleeding.
Menstrual flow is heavy as compared to implantation bleeding.
In short, if a woman has unprotected sex within past few days and she got vaginal bleeding around same days when her menstrual period starts but this bleeding different from her normal menstrual bleeding. This bleeding is lighter, thinner, and of shorter duration than her menstrual period than consider this as implantation bleeding and arrange a pregnancy test to confirm the pregnancy.
Importance of implantation bleeding:
A woman may confuse implantation bleeding with menstrual bleeding and may tell wrong date of last menstrual period to her doctor. This may lead to wrong calculation of estimated delivery date. Any how ultrasound confirms estimated delivery date more accurately.