Basically here is my story. My current girlfriend who i have been with for 4 years is pregnant, but we are unsure who the father is... here is why. She finished her period at around 26th of april, we had sex twice in that week while on holiday and once more the week after, then a week later she had sex with another guy after we had split. I have always believed it was the other guys just through worry and all that, but she has been for a dating scan yesterday and she is 13 weeks 2 days as of the 30/07/2013 which goes back to the week we were on holiday. I know no one can give me an correct answer but id like to ask people what the probability is of it being mine? The nurse at the hospital said the scan is very accurate etc so by the dates and so on its showing to be mine. Nut ive read you cant really get pregnant 1-5 days after you period and when she had sex with the other guy it was peak time of her getting pregnant but the scan dates say different and they cant be 2 weeks out, so what am i to think?