More Frequent Periods

I had unprotected sex about 5 weeks and since I had 3 periods in 2 weeks all together. My periods have always been 6-7 days and heavy all the time, but these periods were 2-3 days and not so heavy. What could be causing this? Someone has experience with this?

This is probably not endometriosis. I think this may cause you do not have a period. It is possible that you are pregnant, but 80% of pregnancies do not bleed. Just to be safe, do a test. It could also be an STD. A couple treatable STDs can cause irregular bleeding. If left untreated, it can also cause infertility. Just to be sure, I would take a blood test your doctor. They can test for pregnancy, STDs and the number of all at once. It could also be caused by fibroids in the uterus, cysts, hormonal imbalance, etc. The best thing to do is check with a doctor and begin testing and to exclude the possibilities.

Endometriosis does not usually cause problems as you describe, or pregnancy. It would be best to consult a health care provider to rule out any serious problem.