Painful orgasm. Is this normal?

I've noticed that after I orgasm, I feel some cramping in my lower abdomen that lasts for maybe a minute or so. Is this normal? I've read that it's safe to have sex as long as you have no existing problems or a high risk. 
Does anyone know if this is normal? Will it always be like this for my whole pregnancy or will it go away at some point? I'll obviously be addressing this with my doctor, but I wanted to know if anyone else has experience with this?
I just want to enjoy making love with my husband without the fear of having painful orgasms or hurting the baby =\