It is possible to get pregnant from pre-cum, but I think that if you used a condom properly and it didn't break then you shouldn't have anything to worry about. It is possible though, because condoms have naturally occuring holes, some of which are larger than the size of a sperm.
Also, generally, when a guy goes soft, doesn't that mean he came?? Maybe i'm wrong, but that's what I always heard.
Daile