Is there a chance of being pregnant

Me and my gf (19f) has sex on 17 july, her periods were supposed to come by 27 and it's two days late. Currently there is no sign of periods

We masturbated however I only ejaculated once she had her clothes on Had no protection but mistakenly I slipped in (ik dumb) just once and pulled out immediately. I did not ejaculate

Is there any chance of getting pregnant . I'm freaking out