Me and my boyfriend just sleep nude on 15th october. He rubbed his penis on my vagina. He ejaculated later in washroom. Both times he rubbed ,he has not precum on his penis. But at night we are not sure if precum was there or not. My last month period date was 26th september. Every month I get periods 4 days prior of previous month date. So I am expected to have periods on 23rd october. But I have not have my periods yet. It there any sign of pregnancy. Can you please suggest me some pills for prevention.