How can I get my SO interested in sex again?

My SO and I had sex recently and had a pregnancy scare, now he's afraid of it because of how badly I reacted to the possibility (previously I had been told it would be impossible for me to have kids). I respect his decision but every once in a while he gets a little frisky then gets upset because he doesn't want to put me through that again.. I want us to have a healthy sex life, one filled with protection and love like we had originally. How can I show him that it doesn't have to be a scary and nerve wracking thing?