Comdom split & toke pill, is my girlfriend Pregnant..?

Ok so me & my girlfriend had sex the other day & the comdom split, at the time we thought nothing of it because she has been on the pill....But that day she toke the pill & she had started to drink alcohol, Not drunk but had only started drinking.

I heard that the pill does'nt work after drinking, is this true..?

Now 3 days later she claims to have been really sick & fainting....& she feels like she did when she got pregnant before.

Is this possible after only 3 days...?

She can't wait to see if she misses a period because shes on the pill & hasnt had a period in a while...

Do you think theres a chance she is pregnant...?

-Thanks