Discomfort after sex??

Help!! Usually, after I have sex with my boyfriend, I get a strong stinging/burning/tingly sensation. When I try to pee, it gets really bad but only for a minute and I barely pee at all. Does anybody know why or how to avoid this?
I don't think it's the type of condoms or lube and it's not a UTI because I'm totally fine the rest of the time (it's an LDR so I'm fine for the other ~25 days of the month when I'm not with him). 
Is it possible that I'm getting small cuts from his chewed nails when he fingers me?? 
Sorry for all the info but if I can figure this out sex will be more enjoyable!!!