PAIN during penetration?!?!

Cas • ✨
Ok so I looooove having sex with my boyfriend but sometimes it hurts! It's not every time we have sex, I'd say it's like 30% of the time but when it does sometimes it's so bad that we have to stop and I just can't! It kinda feels like he's going too deep. It use to happen a looot like every time I did doggy style but now it's only once in a while and happens in all kinds of different positions. Does this happen to anyone else?? Any advice? HELP