What would be the best way to go about this?

I'm a 19 year old male from Australia and i met my 17 year old girlfriend while on holidays in the US. I never intended to get a girlfriend over there but you meet the right one and yeah.. I know most of you will say we're too young but i don't really want a baptist sermon. Anyways, i got her pregnant while i was over there 2 months ago and we still really want to be together. I'm back in Australia now ans shes still in the US, but we want to live together as soon as she turns 18 (or as soon as possible which i ume is when she turns 18). What do you think the best way to go about this would be as her parents dont approve of her having a boyfriend of any sort (overbearing christians). Thankyou for all your help :)