and what do you mean by "somehow"? the only way she can "intake" semen is if you let some go!
so if that's what happened, and you got over-excited and ejaculated in her vagina, or if a condom broke, then yes, it is possible that she would get pregnant "somehow" from this.
the way that would happen is because your sperm being inside her vagina, will swim until it meets her egg and voila! there you have it! 9 months later you have a little pagla running around!
i hope that if you are having sex with your girlfriend, that you are using a condom and using it correctly.