After i have little small bumps on the head of the , does anyone know what it is?

A day after having unprotected i found little red bumps/irritation marks that were very red. About 20 of them going around it, never to close together though. I am uncircised and she is clean. I have never had this before. The bumps do not itch nor do they hurt. I did not use any other products while having like lubricant or any new soaps. I think it mite be just irritated but i don't know.