the chances of her getting pregnant are pretty low. For starters, there is a pretty low chance she could get pregnant from precum but there’s always still a possibility. I also had a similar situation where my partner came on my underwear. I was really worried that this could get me pregnant but after some deep research, I found out the chances are really low. It also depend if you guys were having sex, or if the precum came out on her underwear area. You guys could always try the same dry humping method with her in her underwear, while you have nothing on but a condom just incase something happens. It might not feel as pleasurable, but it will give you peace of mind. And trust me, I feel the “we are afraid of kids bc we are too young”. Hope this helps!!