can pregnancy be possible? she was fully clothed. but has symtoms?

This was about 4 weeks ago and my girlfriend and I were playing around with my pants off. She was fully clothed, and my penis was near her crotch like the higher area, where her button and zipper is? I didn't even ejaculate. She had her normal period, but 3-4 days early, which is normal, it was heavy and not what you call implantation bleeding. She's concerned cause she has backaches and is cramping. She's quite convinced that she might be pregnant, but there is no way she can be right? Tonight, she said that her Montgomery glands seemed to be more visible. She hasn't been eating much, instead of eating a lot like most pregnant women would do. Instead of weight gain, she's actually lost weight. She's been feeling dizzy too. Is there any possible chance of pregnancy?