Am I worried for no reason?

Met my boyfriend in high school about 10 years ago. Started dating, left to college. After nearly 5 years we separated, due to not wanting to be tied down (on either side) and although it was hard, it was ok. After 3 years with no contact and dating other people, we let each other back into our lives. A year later we moved in together. Now it's been 2.5 years and I've never had more of a healthier relationship. We both work hard, and make sure to put effort in our relationship. Living together has been surprisingly smooth. Little tiny arguments always get resolved fast. And I've honestly, never been happier. We've always been super careful when it comes to having sex. But we recently had unprotected sex and didn't make it a priority to get a plan B pill. He doesn't seem to mind the idea of having a baby. And a part of me doesn't mind either. My plan was to wait till I was at least 30 to have kids. I'm almost 28 and I've been a nanny my entire life so I'm comfortable with babies 100%. But I'm always worried, about how he'll be if we will have a baby. How I'll handle being a mom. Just everything! I always wanted this "at the right time". Now I'm kicking myself for having this slip up. Do you think it's too soon? Or is my over thinking getting the best of me? 😓