Aimee,

Have you started or switched to a new birth control pill?  I would also get checked for ovarian cysts.  Many years ago, I had cysts and while I did not have heavy bleeding with them per se, the cure was with birth control pills and they did a number on me with the same exact symptons as you described. It turned out it was a case of them 'bursting' and the pills. In any case, I would see a gyno asap about it as it can also indicated much worse things too.

Best,

Betsy Driver

http://www.bodieslikeours.org