Even if she didn't swallow, it would still get to her throat (some of it anyway). An allergic reaction usually presents itself within 24 or so hours, so 3 days is a bit long. If it were an allergic reaction is would happen after every time giving oral sex.
Sore throat, white spots on throats, swollen tonsils etc are all signs of tonsilitis. I suffer from this a couple times of year and have done since I young child, and that's the symptoms that usually present themselves.
it sounds like an alergic reaction from his fluids. doesn't mean he necessarily is infected with something. drink plenty of water every day; room temperature water so you can consume more. for the future, don't let his fluids get to your throat, avoid swallowing...
I don't think it's an STD, sounds more like you have tonsilitis.
It's possible that maybe you have some kind of reaction to his semen, but that would most likely present itself sooner than 3 days post oral sex.
Spotting can be from a number of things too, and isn't connected to the sore throat/oral sex.
Also forgot to mention, I noticed that I am spotting or just having vaginal discharge. I have small amount of blood on my underwear. I know he did wear a condom when we had sexual intercourse though.