me and my girlfriend had sex yesterday, the condom broke but I noticed and stopped ( I didn't cum) ... what are the chances of her getting pregnant... I no I didn't actually come but there is always pre-cum ?
Of course there's a chance but not as much as if the condom had broke while you were cumming. Also, it'd have to be the right time of the month for her taking into consideration that sperm can live and stay present in her for several+ days afterwards. For you right now, I'd say it's a wait and see and hope that she didn't get pregnant. Your chance are very good that she didn't, but definitely not 100%.
First, condoms break from mishandling. Check your storage, your lube (no petroleum-based products, right? you're using plenty, right?), how you handle the packaging, everything that happens to it from the store to the bedroom. They're only a few microns thick. You can't be rough or careless with them.
Second, figure out emergency contraception, for times like this.
Finally, the chance she's pregnant is small, but it exists. If you haven't had the "what if you get pregnant" talk, then now, right now.
There is usually a little spermicide in the lubrication that comes in the condom, so it should be ok. But as always, if your girlfriend can't get a hold of another form of backup like the morning after pill (or whatever its called these days) then she should wait about two weeks then have a pregnancy test just to be sure.
But I'm 90% sure she shouldn't conceive, so don't stress 'too' much.