I had sex for the first time with a sexually active girl. I tried unsuccessfully to put on a condom twice, so I asked her if she was clean and she said yes. We had unprotected oral and vaginal sex and as soon as I withdrew I saw a small red spot/blister on the shaft of my penis. I thought it might be blood from her but I had a shower straight away and it did not clear up.
Perhaps it might have been caused by her teeth or hand prior to intercourse, but I'm wondering is there any STD that shows up that quickly?
Nothing shows up THAT quickly. Most likely it is some sort of irritation.
That's what I thought. It's in a spot where I've noticed a lot of sensitivity where the web of my hand rubs during masturbation. Thanks.
I wouldn't have thought anything would be that quick to manifest. I would seek your GP's advice and then also make sure you use protection in the future. A good slogan is "no glove, no love". Always good to be careful and protect yourself at all times.
First mistake is asking someone if they're "clean". Sebond on is taking what they say a face value. If you're having sex protect yourself and your partner.