It is August 4. I ended my period on July 26. I have recently switched birth controls from Ortho-tri-cyclen to YAZ. This is my second pack of pills. During the first pack, nothing abnormal happened. Two days ago i began bleeding heavily along with blood clots. Heavier than my period usually is. And obviously it is not time for my period yet. I did this two months back and had bleeding for 21 days straight. Not time for my period also (thus the reason they switched my pills). I have severe cramps, unlike period cramps. Does anyone know what this could be? i have heard breakthrough bleeding, but is it this heavy?? it just doesn't seem normal! any advice would be appreciated! p.s. im going on vacation with my boyfriend in 4 days and i would really love to not be bleeding: )