I’m sore after sex

I start cramping after sex really bad, and can rarely go for another round. Is this normal? For context, I’m pretty small, and my boyfriend has an average to above average sized 🍆. Everytime we have sex, of course it’s absolutely amazing, but I feel pain in my lower abdomen, and am left sore. I can rarely go another round. Is this normal? What can I do to fix this?