Yeah, precum can also make you pregnant and is always present at some time during excitement, or intercourse. Just because he supposedly came one time without ejaculating doesn't mean it will happen every time or even again. Some men do say they have "little orgasms" where they don't ejaculate or ejaculate very little, but you don't know unless they do where a condom and there is nothing there. So, it is very likely that he did cum inside of you. And we as women know how that feels, so I am sure you would know even if he isn't sure for some reason.
If this happens again make sure you get the morning after pill in time. And maybe you should consider going on birth control also, so that if a condom breaks you don't have to worry so much.
Good luck, hun, I hope it all works out.