5 months TTC

How long has everyone been TTC. I feel like it's been forever. With my first two I became pregnant almost instantly. (Different guy that who I'm with now) It worries me that he might have issues concieving. He used to be quite the man whore in his younger days. He hasn't worn a condom since he was 18, but has yet to even have one oopsie baby. I'm just worried. But I don't want to worry him and bring it up to him yet. 
(And no he doesn't have any diseases, or anything from being careless)