endometriosis
"I had an absence of periods for 6  months, I'd be lucky to get one period a year. I thought something was really wrong with me and I was freaked out. Luckily I did a 10-day hormone therapy thing and then got put on birth control. You will also feel crappy the day after you take your first pill. It's normal, your body isn't used to it so you will feel crappy. I had such a bad headache that I had to leave work early. But besides that, Sprintec has been great for me! I have a period at the end of every month, for some reason it's the THURSDAY I start the white pills. The only side effect I've had is a yeast infection because my body wasn't used to the increase in estrogen."