Can I have a different baby father ?

In January I had unprotected sex with my previous baby’s dad , we were working on things. He nutted on me but not in me. Prior to that I had protected sex with a guy I was in the process of ending things with. Now I wouldn’t think twice about it but the baby doesn’t favor my baby’s dad that much. Idk if it’s just cause he looks like me. But I don’t want to get my ex DNA tested cause he’s 17 (currently) and I’m 23. I had no idea until months into our relationship he had a fake ID and I just didn’t pay attention that well 🤷🏻‍♀️ I just don’t want to stir a pot up by getting him tested. I mean if you can get pregnant off of what my baby father did I’m sure you can get pregnant with a condom , right ?