Possibility of Pregnancy? we would like an expert opinion

Dear doctor/community,

I have posted this in the general forum as well, but it seems that I might get a better answer here. I apologies for the repeat post.

My girlfriend and I were playing around last night. Without touching her beforehand, I wiped some pre-cum from my penis and then washed my hands with soap and then antiseptic. I then used the same hand to finger her. She is worried that she might be pregnant.

She has been on the pill (Ginette 35) for the best part of four years and has hardly missed a day (last time she missed a day was two weeks ago). We have not had intercourse during our relationship and did not last night, but we are still rather paranoid.

What is the likelihood of her being pregnant based on the circumstances? Somehow I feel that the chances are very, very minute but we would like an expert opinion just to ease our worries. Is there ever a chance that she can fall pregnant on the pill?

Thanks for your reply.