Help?

Me and my so have always had unprotected sex our whole relationship, we got tested first and I have the implant birth control that is like 99% effective. I don't worry about getting pregnant because I know it is very unlikely, but my SO gets so paranoid. If I say I have a stomach ache or if I'm bloated he asks me if I'm pregnant. He's actually had me take a test. I try to talk to him about it and he said he just worries. It gets really annoying and I kind of take offense to it... Should I start using protection? What should I do?