Blister

Ja
A couple weeks ago, I noticed a bump between my vagina and my anus, kind of to the side on the lip (seems hard to explain!). Today I finally got the courage to ask my husband to look at it because it was making me nervous, and I was diagnosed with HPV about 4 years ago (tests are all healthy and clean now and neither of us had any side effects). 
He said it looks like a blister to him, almost like it's from rubbing. It's been really hot here lately (we live in MN) and I've been working out on my lunch breaks at work and then changing back into dresses/skirts. 
Has anybody ever had a blister...down there?