Hi, I Was Recently Told By A Girl I Had

Hi, I was recently told by a girl I had been with was pregnant and she is claiming that it is my kid. We never had vaginal sex but we had done other stuff. If she did get pregnant, the only way would have been if I had semen on my hand when I fingered her. If this was the case it would have had to have been a very small amount that was hardly visible, if visible at all. She was also on the pill at the time and took Ella between the third and fourth day after the event. It seems extremely unlikely that she had gotten pregnant but she has been confirmed to be pregnant with a blood test and hearing the fetal heartbeat with a sonogram (I can not attest to this but she has told me). I would like to know what your opinion on the matter is. Also, she mentioned that her gynecologist said she didn't think her birth control pill active pills were working. How is this possible, does the pill simply not work for some people?
Thank you for your time and I apologize for the long explanation.