Assuming it's an oral herpes outbreak - has she had one before? Does she know that she has this? - then for sure there is a chance you got it, if you don't already have it. About half the adult population does, and 90% never get a symptom.
Test now with a type specific IgG. Don't bother with the IgM. It's unreliable, and shouldn't be done on anyone but infants. If it's negative now, then test again at 12 weeks, or if you can't wait that long, and can afford it, do it at 6 weeks, too.
The incubation period is 2-20 days, with the average of 4 days if you are going to get symptoms.
You didn't notice until you were kissing her that she had a boil (not usually herpes) on her mouth? It's always a good idea to not let someone with any kind of sore on their mouth kiss you or perform oral sex on you. You don't know if it's a herpes sore, or something bacterial, etc. Maybe she just had a big pimple and chapped lips.
There's no need to freak out here, or over test. Please don't make your girlfriend feel bad, or like a walking infection. It couldn't have been that noticeable if you didn't notice it until you were kissing her, and you still let her give you oral with a sore on her mouth.
Thank you very much for your prompt response, you have no idea how much it helps when you responded so fast, appreciate your time and help.
So I saw my gf again today after 6 days of possible exposure, her lips looks completely normal today (just dry inside) the lines over the top and bottom seem to be intact and no sores or swelling but some patchy yellow dryness inside the lips. I explained to her all the possibilities and she told me she got tested last Saturday and all her results are negative (Again she didn't tell me if she did any herpes test, she doesn't understand all these things).
Well I don't want to make her feel bad but since I care for her I started to ask for symptoms and she got pissed off, she thought she caught something serious from me, since she saw her results negative today she says she forgave me
Anyways, how long can these sore heal by itself? I know she told me she had sores from a week before I met (ie last week) so today is like 3rd week for that episode, would it completely disappear? She never had any genital symptoms for sure only oral is my concern for her, I know what I saw was very much matching herpes symptoms with red sore over the lips (not under)