Pregnancy worries about my girlfriend

Hi I'm very worried about my girlfriend nd wheather or not she's pregnate. Onthursday the 19th we were alone nd I started to finger her and she started to rub my penis until there was precome on it nd I had stopped her at one moment bc I thought that someone was coming so I put it back in my pants but I can't remember if I touched it if I did then it was jus for a brief second nd then when I realized that no one was coming I whipped it back out but didn't touch any off the penis only the balls after I continued to finger her I'm wondering since the precom was exposed to air for a while. D if I may have fingered her after I touched it briefly if she may be pregnate any help is appreciated thanks nd yes I'm very worried nd I'm 16