I shaved with an older razor then had sex a few times with my partner. Started to have itching from razor burn. Now I have three pimple looking bumps (smaller than a pin head) that are in a line above my vaginal opening. What is it?

Needs to be seen. Lumps, bumps, blisters and other skin abnormalities on the genitals need to be evaluated. An examination will be needed to know the cause and treatment. Folliculitis is one possibility. Yeast is a possibility and over the counter fungal cream will fix it. Trauma from recent intercourse if possible. Herpes is an std which can cause this. Other possibilities too. Schedule an exam or a virtual visit.