Firstly is it legal where you are to be messing around with a 17yo even tho your 19???
Ey, "never" is a strong word. Ive found from experience that women who say never to sex and actually mean it, either have one of two things:
1. A bad mental issue that could be something that had happened to them in the past or possibly something currently plaguing them. If this is the case, again from experience, run for the hills. Its not your problem until you make it your problem. If you want to dive into her dark past and try and bring both of you out of it alive then, well thats dumb, but if you do it your my hero!
2. She has a strong religious background, belief, lifestyle... in which case just downright run for the hills!
If sex is that important to you then you need to ask her what her reason for not having sex is. If its honestly just a case of shes not ready then go the 6 months with a little bit of wine and dine along the way.
This advice is all given on the assumption that your a nice bloke and im only taking you into consideration. If your not and you consider this to much work and you just want a quick and easy solution and its legal, shes 17, be the alpha, whisper in her ear every chance you get, sweet talk her about the topic as much as you can and if she really likes you eventually you'll get in. BEFORE ANYBODY FLAMES ME, i have never done such a thing myself or would do such a thing.
This is getting a bit long so if its the first few things i mentioned there is no point making your life miserable over a girl not willing to compensate or commit or at least try. But if you like her then you should look at would you feel better having a gf who doesnt go all the way or nothing.
This is all a matter of opinion btw DO NOT take all this to heart, im sure there are other opinions coming.
This could also help>
she says 'i feel like a slut/whore'