Oh man!. help!. should i be worried or am i over-reacting?.?

okay.. so my girlfriend and i were makin out real on wednesday.. it was niceee.. we were both hella horny and i didnt have a condom.. sooo she was so horny that she told me to stick it in once.. just once.. and so i did!. but it was only for three strokes and then i pulled out cuz it was far too risky to keep going.. i wasnt in her for more than 7 maybe 10 seconds.. and no, i did not .. but im still concerned.. i told a lot of my trusty friends and they all told me im over-reacting.. they told me nothing is gonna happen but then idk.. i also know that there is no sperm in pre as recent studies show, and it makes sense.. pre *** is just to clear out the urethra and to lubricate.. but today, on friday (2 days after), she had a white l discharge.. and other than that shes been feeling fine.. could this white l discharge be a sign of pregnancy or am i worrying too much.. i kinda feel like im worrying too much cuz i dont think symptoms show up 2 days later.. well, i want to know what you guys think.. what do you guys think about this? am i over-reacting? could this white l fluid discharge be something else? help! i'm worried! :(