What Causes Vaginal Spotting And Bleeding After Periods?

Hi, may I answer your healI had a baby the end of April and got the depo provera birth control shot on june 23rd, which was 2 days after i had started my first period after the pregnancy. my period had only lasted 2 days so it had actually ended on the 23rd also, before i had got the shot. I got my period about 3 weeks ago, and had it for 2 weeks straight, very heavy. i have only been off my period for a week now, last night i started spotting very lightly. then this afternoon i had not noticed any spotting, and had intercourse, during which i started bleeding and now i have like my full out period again. help!th queries right now