Is it me ?

Ladies ! I need some advice. My boyfriend and I are fairly new in the official terms of dating. We’ve been having sex for a while now. But he’s never actually came. And I mean I always ask if there’s something I can do to help or whatever. But he says he’s good, he’s satisfied etc. I’ve never been with a man who can go for hours and still not finish. So I’m starting to feel a little worried maybe I’m doing something wrong ? Has anyone else been through this ? Maybe some tips and tricks to work through it ?