My girlfriends parents won’t allow her to go over the weekend with me because they don’t want any “unwanted pregnancies“

I’m 19 male. My girlfriend(18F) and I have been together for 10 months. We’re planning to go away next weekend to do some hiking and to stay in a hotel.

My girlfriend’s parents are saying she can’t go because they don’t want any “unwanted pregnancies”. We have sex, we have for most of the 10 months we’ve been together. We’re responsible and not stupid. My girlfriend is 18, they can’t control what she does now, right? My car is broken and is only due to get fixed in a few weeks, so my girlfriend was going to drive us there but after she told her parents about her going, her car keys have gone missing… she asked her parents if they have seen her car keys and they said they took and hide them. She bought the car herself, puts fuel in it and pay for the up keep, yet they’ve taken the keys like they’re theirs.

A couple of months ago when I was at my gfs house after uni, my gfs dad went through my backpack and found condoms and he lectured me on it and told me I better not be using them on his daughter. They aren’t religious. But they’ve never liked me, I’ve never done anything around them to make them not like me, always respected them and been polite, and I’ve never gotten into serious trouble in general.

All the garages are booked so there’s no way I’ll get my car fixed in time, everyone in my family is working when we plan to go so none of them can give us a lift. None of our friends have cars. I think I’m too young to be accepted for a car loan.

Advice?