Life has been very busy for me these past 2+ mths so I've not been as active or posting much lately. However, I read your post and the replies and felt the need to give my perspective and share some knowledge and experience with you.
First, I'm not sure what kind of testing you've had done, but you yourself could very well have had the HSV virus for some time now and weren't aware of it. Just because you're having a first OB a few mths ago, does not mean that you've only had the virus since then. Some people who carry the virus can go months and sometimes yes, even years, before ever having a visible outbreak (or for that matter, ever have one at all). So at this point, your g/f should indeed be tested, whether she's had symptoms or not. You both need to be aware, not just one of you. You should also be aware of which type you have as HSV 1 can indeed be passed on to the genitals, just as HSV 2 can be passed on to the mouth (though research and stats. thus far indicate HSV 2 orally, is rare/uncommon - none the less, it's still a potential risk that needs to be addressed).
Another reason for your g/f needing to know if she has it, just as you're aware that you do, is the simple fact that not all relationships work out....which is not to say that yours won't, but it's not about that anyway. Plus, if she doesn't have the virus at this point, you should both be aware of the risks involved to the partner who's herpes free. Many relationships have and can work with one having it and not the other, but you both need to be aware of the potential risks so as to avoid passing the virus on, orally and/or genitally.
Now, all of the above said, I was diagnosed with the virus late August of 2006, so only 4.5 mths ago. I ended up having 3 OB's pretty much back to back within a 6 week period...was very distressful. Valtrex didn't seem to work or do much for me...what I had better success with was Famvir....but the virus will behave differently in each of us so you have to find what works for YOU. I will say this though, it's now been 3 mths or so since I've had an outbreak...and my Dr. actually suggested not to begin or start off with suppressive treatment, as the virus needs to establish itself and therefore allow our immune system to build the necessary anti-bodies to fight said virus when it becomes active. Some don't ever need to go on suppressive therapy as their immune system indeed may be stronger than another persons. Again, each of us are different. Until I know how my body is going to react to the virus, which will take 6 mths to a year (from what I've been told) my Dr. sees no logical or medical reason to begin daily meds. She had me take my meds only as eposidic treatment, however after having my 3rd OB in such a short span, I decided to take a 2 week suppressive dose of Famvir to see what would happen while on it and then after stopping the meds. I did not have another OB and when stopping after that 2 week period (approx.) I still did not have another OB...and currently remain OB free (fingers are crossed and I just knocked on wood, lol). Now does this have anything to do with my taking the Famvir daily for 2 weeks, I really don't know.
What I can say for sure is that some of us are indeed lucky enough to not have continual OB's. I'm estatic that I remain OB free at this point as I've heard when women are symptomatic and first diagnosed, it can be much worse than what I've experienced...some have OB's monthly....my heart goes out to those who have recurrent OB's. So again, for your g/f's sake, it's best that she find out whether she has the virus or not.
If it turns out she has the virus, there could be a real possibility she's asymptomatic if she's not having and still hasn't had any OB's...most especially if you've actually had sex in the past where you've had an open sore but didn't realize what it was. That would mean she's been exposed more than once to the virus but seems not to be reacting to it....either she's DARN lucky she wasn't infected by the virus when exposed to it, or she's indeed a carrier who thus far has had no visible OB.
At this point, if she does test positive, there is no way of knowing who may have passed it on to who, or for that matter, if it was either of you who passed it on to each other at all...that's another possibility.. So IF you are both indeed positive for HSV, unfortunately the "from who" and the "for how long" will likely never be answered. SO, if that part is an issue for either of you, my advice is to let it go and not focus on those aspects at all...won't do either of you any good.
So, there ya have it....a long reply, but I feel it's worth it. Every new person diagnosed and looking for answers and guidance should be well informed and if I can offer anything in that search for knowledge, that's why I'm here!
Good luck to you and your girlfriend...and welcome to the forum! It's really a caring and supportive bunch here!!