A Bump?? Down there?

Okay so today me and my SO had some alone time so we decided to have a bit of intercourse while we had the chance. It has been awhile since we've done this and we wanted to take advantage of the time as much as possible. So without thinking we started to do it and at first neither of us noticed something horrifying. After awhile he stopped and looked down and then reached his had down to feel what was going on. When he felt around I felt a pain and he looked at me with genuine fear. I was confused and so I reached my hand down and felt a bump!! Down there!! It's really painful and honestly scarring me! I've checked the mirror and it's about the size of a pea but I don't know if it's a pimple in an odd spot or something more. Could this be a tumour or something worse? Please help I'm really concerned!