Can you get pregnant using someone elses lube?

I know it was stupid, but I ran out of my own Lubricant, so I used some that I found in the bathroom cupboard, I think it may have been my brothers and his girlfriends, I only used one pump of it. And I don't think they'd used it for a day or so, if there was any sperm on there would it of died? I'll know never to do it again! But I'd just like a little reassurance.