Last month, mistakenly i was engaged in unprotected sex with my gf before 10-12 days of her period. I entered into her but i took myself out of her when we realised the possible threats. I entered less than a minute and did not ejaculate. After this she had her first period which was normal as usual. But this month means her second period after that event is not on time or in probable days. Is there any possibility of unwanted pregnancy? Please reply how to confirm about pregnancy and guide us.