abnormal uterine bleeding
"I've been on the depo shot for 9 months now. I love the ease of use, only having to get a shot every 3 months is beautiful if you're a forgetful person like me and struggle a bit with remembering to take the pill at the same time daily. No pregnancy worries! I'm also less moody on the depo shot than I was with no birth control and when I was on the pill. 
Con: However, biggest downside and the reason I will be switching back to the pill within a month, there has not been a 24 hour length of time during the past 9 months in which I did not bleed. I have bled, in random amounts, daily since I began it 9 months ago. It's horrible during and after intercourse, if I do kegals, if I work out, nothing can stop it."