I have an underage girlfriend...

Oh myso many people are so uninformed here. Its a 3 year difference and you would have nothing to worry about in the statutory since. Thats like a freshman dating a junior and you cant walk into any HS in the USA and NOT find that. Now laws can vary from state to state but you wont find DA that will prosecute this unless the contact was forcible. The people in here telling you to run just dont want to hear/read about one of their peers having sex because they themselves, are nowhere close to having sex.