Periods 2 weeks too late! Could my GF be pregnant?

My gf told me that her period has been late for 2 weeks. She thinks that it may have been the stress from the national exams and projects from school. However she told me that her period has been quite regular and on time until we started playing around. Is 2 weeks late a little too long?

We have been playing around a lot. I would finger her, and she would give me an oral. I have only given her an oral twice. And I have not cum-med at all during all these times we played around.

The only way for her to be pregnant is that, she had pre-cum in her mouth when she gave me an oral, and then when we french-kissed that pre-cum transferred to my mouth, and after which, when i gave her an oral, the pre-cum went into her vagina.

OR i may have accidentally touched my penis with pre-cum and fingered her, but my fingers dont go all the way in, they only stay on the outside. (As in my fingers dont go into the tight tunnel. Sry if this is too explicit)
But isn't this a little too far-fetched? i mean the chances of pre-cum impregnating a person is slim and not only that, but it was transferred so many times.

Advice of any kind would be very much appreciated, thank you very much. Really, ty.