I not really had sex but I stuck my penis about an inch into my girlfriends vagina and I had pre cum, could she be pregnant? I had peed 3 times before

You have had sex. . Pre-ejaculate may contain large amounts of viable sperm (less common), smaller amounts of sperm that are dead or alive or no sperm. There is potential for pregnancy with pre-ejaculate. Sperm need to be deposited in vagina or at introitus for pregnancy to occur. Use protection every time you have sex if you’re are not ready for pregnancy. She should take a home pregnancy test if late.
That's intercourse. You penetrated your girlfriend, and that's sexual intercourse. There's a low possibility of pregnancy. Use a condom next time.