My Gf Is Having Head Spins For The Past Two

My gf is having head spins for the past two weeks. She is not having periods as she used to. As per her the periods are very light which are lasting for one or two days. But they are happening at the right time. She is taking a lot of stress for these and is thinking about it all the time. We have never had sex. But we had a day where we were too close and were indulged in only foreplay like kissing and fingering. She is scared that she might get pregnant for that. Is it possible for her to be pregnant? She thinks my fingers had some sperms in it which might have made her pregnant. Please advise.