I had the opposite happen. When I was a virgin, my periods lasted between 7 and 10 days. After I started having sex (I was 20 the first time) they shortened to between 5 and 7 days. My doc told me that there is a link between the two. He coudln't really explain why, just that there is LOL.
have you been stressed out/upset lately? I know if I am it will mess with my period. Also with me, if I start my period earlier/later than expected it will be heavier then usual. Maybe if this happens more then once you need to go talk to your doc and make sure nothing else is going on. OH, (sorry if this is TMI) if me and hubby have rough sex a couple days before I'm due for my period, it will be heavy that go around. No clue why :)
at 12:57 PM on Nov. 2, 2010