I'm keep getting my period everytime I have sex????????

My boyfriend and I habe been dating for over a year and a month or two ago we started having sex. I'm on birth control and he uses condoms. every time we have sex, as soon as anything goes into my vagina its painful and I start my period. we had sex yesterday and while we were having sex, he pulled out a nd there was a piece of tissue on the condom. I wore a pad all day, all night, and all day today. it's been about 24 hours and I just got my period , but my period isn't very liquidy. the tissue doesn't break down properly and comes out as dark brown almost reddish black chunks between the size of a dime and a quarter. Is any of this normal? Should I talk to my doctor?