Can you get oral herpes from someone who doesn't have it?

You should go for STI tests periodically anyway, so get checked out. No harm in looking after your sexual health :) don’t worry, I’m sure you’re fine.

First, it’s probably not herpes. Second, even it is, you are mistaken in thinking that both of you are negative for HSV. Most people assume it is from kissing and sexual activity, but that is only one way to get it. For instance, if a parent or aunt or sibling has it, and they kiss you, or you share a cup, etc., you can catch it (or have already caught it at a young age). It can lie dormant for years before flaring up. So, it is often nearly impossible to pinpoint who gave what to whom.

I agree with @shilolo, it’s probably not herpes. However, if you are old enough to be sexually active, you should be getting tested. Planned Parenthood is a good resource for that if you don’t have health insurance.

Oh, and, don’t stress out over it. :)

@shilolo on the contrary, most people can pinpoint when they contract HSV as the first outbreak is typically the worst and occurs within 15 days of exposure in something like 85% of all cases.

It is true that there are a number of ways to be exposed, it may have nothing at all to do with your boyfriend. It does not sound like the symptoms of HSV to me, however it’s probably a good idea to be tested anyhow. Always better to have that peace of mind. Best of luck to you :)

@TheOnlyNeffie When I was young I contracted HSV-1 (cold sores). I don’t remember my age at the time, but I do remember for the longest time thinking they were just fever blisters or some such. I really didn’t know they were part of the herpes strain till much later. But even when I did find out, I really didn’t care because at the time it seemed (and still does) that no one really cares about cold sores. Too much of the population gets them, and since they are right there on your face where you can’t hide them, they’ve become almost the ‘norm’.

Now, HSV-2, the genital form of herpes. THAT is still a big taboo. Strikes me as odd really, that the same virus would cause two different reactions among the masses.

@TheOnlyNeffie Not true. Many people that get oral herpes (HSV-1) get it as children. In those cases it is frequently manifest as oral lesions (not like the classic cold sore) or a simple sore throat or nothing at all. A child with a few vesicles in their throat or complaining of a sore throat could have any number of viruses, and as such, pinpointing the exact time of onset of oral herpes is challenging at best. Indeed, the majority of people who develop oral HSV (fever blisters, cold sores) cannot identify who gave it to them. Likewise, many (I would say most) people who contract HSV-2 never know it. In both cases, this is due to the fact that people can be infectious/contagious without outward signs of disease.

It sounds more like a simple case of aphthous stomatitis, a painful but ultimately harmless and apparently non-communicable condition.
Cause unknown, cure nonexistent, and it is not being researched by anybody, since all the grant money these days is being poured into diabetes, cancer, and heart disease.
Wiki lists treatment options. They should go away in a couple weeks.