I've had depo-provera for a year now, at random times i get heavy bleeding and somewhat big clotting. i had an ultrasound done, & said i was fine. any ideas?

Unpredictable: The bleeding patterns with depoprovera are unpredictable. For some in takes the period away. For others it causes irregular bleeding. There is no "normal" for Depo-Provera users. The longer you are on it the higher the chance of no periods. Annoying but not dangerous. If you are unhappy with the bleeding pattern on Depo-Provera consider a Mirena (levonorgestrel) iud.