How do you know that it wasn't your fluids inside the condom?
Herpes doesn't spread by fluids. It spreads by direct skin to skin contact. Your chances of getting herpes while using a condom are very, very low. I don't know what your bump is, but herpes causes blisters, not bumps.
I don't think you need to worry about herpes. Bumps can be caused by many different things, some sexually transmitted, many not. If it doesn't go away in the next couple of days, or gets bigger, or spreads, any urgent care center can help diagnose it.