Scared to do it Again.

I've had sex with my partner twice, both short but very nice experiences, except for the pain. I broke my hymen (assumably) a long time ago, but when riding him (girl on top), or going doggy-style, there's deep abdominal pain, almost like throbbing or cramping. The pain is bad enough where I'm crying out and needing to take a quick break. It hurts especially when he's thrusting in. Changing positions/angle usually makes it better, but definitely ruins the experience for me, as I'm scared of physically hurting again. He's not dramatically large or rough with me at all. I want to be able to enjoy sex. Thoughts?