PLEASE HELP

whenever my boyfriend and I️ have sex, i always end up bleeding or spotting afterwards. He fingered me after we had sex tonight and realized i was bleeding. i made the excuse that he cut me with his fingernail. this never happened to me with any other guys and it can’t be any type of STD because i’ve been tested multiple times. i️ also have no symptoms whatsoever of any infections. i’ve been told that it could be because of the lack of lubricant, but that honestly doesn’t seem to make sense either. he always eats me out before or we use lube. im just so confused as to what my body is doing, HELP