Help?

My boyfriend and I have started having well sex and we have been for a little while now, we don’t do a whole lot and neither of us finish, but when we do try it (sorry if this is tmi) but i get a bit of a burning sensation down there, he’s my first and im his, I’ve been on bc for almost four or five months now, not only does it burn but i don’t feel much at all, only when he hits my cervix and that’s it, i don’t know why this happens and I don’t know if it’s a side effect or what but he doesn’t know about it and it makes me feel terrible. Any ideas? PS I was curious if the burning was from not being excited enough because he doesn’t do foreplay very long, and this makes me a bit sore sometimes.