Pregnant sex

How do you girls do it?? When I get in the mood I cramp so bad to the point of tears. I feel so bad because it's been like a month since we've had sex. But I can't even just pleasure him because that turns me on and then I cramp. Im 12w. Been cramping like this since about 5w. I try to put up with it sometime. I mean it goes away after while but it just hurts for so long it's not even worth it for me. And he understands and doesn't force me into it or anything. I'm just wondering if anyone else is going through the same thing or if anyone has found a way to make it work?