Boyfriend or paranoid

So I have been with my boyfriend now 13 years. I'm 16 weeks pregnant and have been faithful. But recently he has been complaining his penis hurts like painful hurts. He has a penis piercing and has had it for nearly 10 years and he was has been saying it hurts. It makes me paranoid that maybe he might have something or has been unfaithful and brought something home. How do i find out without being rude about it or having him think I'm not trusting