Unprotected sex July 4th. July 20th I experienced light spotting, which was 6 days before my expected menstrual cycle. July 26 I got an actual menstrual cycle, a normal one for me. However, every month since I have been having an extremely light menstrual cycle which resembles more like spotting for a few days. So much that I don't bleed overnight, which is not like me. I started my cycle when I was 10 years old, and I am now a few months shy of 21. Never before has this happened to me, and I have never been a light bleeder. I've taken two urine tests so far, both coming out negative; one home test the other at a hospital. I have also gained weight which is only going to my stomach area, a noticeable amount of weight gain. I believe that something is wrong, but I keep getting negative results.