damn dude i did the same exact thing and im freaking out because i didnt think anything could happen, just waiting.. well just tell me what happens, good luck
ok so the people up there are completely right, im sorry, but just relax, she could jsut as very easily not be pregnant and she could be pregnant. you and your girlfriend jsut need to relax as long as you can, if she doesnt get her period then take a test but intil the missed period, just be happy and enjoy life...with no sex. lol 15 is faaaar too young, im 19 and thats still too young for myself and my boyfriend, sex is good and fun and all that but it also comes with a sensible and mature brain, so just hold out on it, you've got a lot f time to worry about sex later!!
yes she could be pregnant. even if it was only for a few seconds. if you were aroused you MOST LIKELY secreted pre ejaculatory fluid which DOES contain sperm. she's going to have to wait at least 2 weeks and take an hpt.
Did you use any form of B/C? Condom or other contraceptive. It only takes one to get a woman pregnant ( and pre-ejaculate contains semen), you don't know if you pre-ejaculate, you can't feel it. There's a chance shes pregnant, you'll have to wait until her periods due/missed and take a HPT. You should use a form of B/C to prevent future pregnancy scares and STD's, good luck!