Friction blister?

[Horizontalrunner]

I recently had unprotected sex with my partner Saturday morning at 3am. The sex was a bit rough and there were moments when it was dry. The sex lasted 2 hours. Afterward I felt sore and a bit tender. Within 9 hrs I noticed a itchy feeling on the right side of my vag lip towards the evening I decided to take a mirror and look and noticed a blister (just one) the size of 2-3mm. It looked like the kind I would get if u bit the inside of your mouth. Sunday morning I woke up and noticed a lot of discharge as soon as I got out of bed and when I peed it stung. I looked in the mirror again and noticed it looked like it popped. Inside was white with a red outline. I was recently tested 3 weeks ago and the tests came back negative. The blister nor the discomfort was there before we had sex. I have learned that STD/STI symptoms usually start 72 hours after sex. So I am a bit worried and confused.

[TooHip1973]

Your best bet is to get into the doctor or urgent care clinic today to have the sore swabbed. If this developed over the last few days, it could still over a viable sample for hsv swabbing.
When you were tested 3 weeks ago, was hsv testing included? Most standard std panels do not include hsv unless specifically requested. You might want to confirm that and confirm if it was an IgG test.
9 hours is really quick for symptoms to show up but if you haven’t had sex in the weeks prior to that, then it wouldn’t be typical for hsv. Not impossible I suppose but rare.