Last time I checked I dont think sperm got up and walked off of your leg and jumped into your vagina and made a baby, hehe, so no I would not stress about it. Buuut, it does seem you and your gf are getting very curious and wanting to explore eachother, so before any of it starts, she should probably think about getting on birth control, and be sure to have some condoms near by, even if your not having sex now, it doesnt seem it will be long until you do, so if shes already on birth control and stuff, you guys wont have to worry when you do decide to take the next step (though please feel free to take your time, hehe) but I know how it is. And if parentals are a problem, she can always go to planned parenthood and get birth control and all that for free, its really easy, let me know if you want more info on that, ill be glad to help. Well you guys be safe! Be responsible! Have fun :)