### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
I had sex with someone on Jan 31,2014 and used the pull out method, then had sex with my boyfriend on Feb 2,2014 and he did ejaculated in me. my last period was Jan 22,2014 and on my calendar it says my fertile days are Feb 2-9. Can Jan 31 encounter be the father even though he did not ejaculate in me? Thank you.

### output:

Hallow Dear, The egg is released (ovulation) 14 days prior to next expected menses. Considering that egg has life of 24 hours and sperms are active for 72 hours, a period of about 8 days is fertile period. You had period on 22 January, hence your next period would be on 21 Feb. (considering your period of 30 days).  So the ovulation day falls on 8 Feb. Thus the fertile period would be from 3 February till 11 Feb. If your period is different from 30 days, please add or subtract those many days in this calculation. According to your calculation, the fertile period starts on 2 Feb. So the chances of pregnancy due to intercourse on 31 Jan. are remote, though cannot be completely excluded, since variation by couple of days has to be expected. It is too close to the fertile period. Though there was no ejaculation, you cannot exclude pre-ejaculation fluid passage which happens unknowingly. It does contain some sperms which are capable of fertilizing an ovum. So though the maximum chances of conception are due to sex on 2 Feb., for legal purpose, you may opt for DNA test to ascertain the paternity. I hope this helps you. 