weird white painful (only to the touch) bump in between minoras.

Yesterday, i had sex with my boyfriend (unprotected, that's how we usually do it) after a week of not having sex. He pet his dog before coming in the room and I stupidly forgot to tell him to go wash his hands because i missed him so much and wanted to get into action. After we had sex, i went home and when i got to shower, i was washing my area to feel a bump which hurt when i touched it. i'm really scared. I checked this morning and it was a sort of off-white color. i need help!