safe times

Is it safe to have unprotected sex ten days after a period?

I had unprotected sex with my girlfriend 2 days after her periods was over, as she told me that 10 days after period are safe to have unprotected sex. Her last period was 27th October. Well today, 19th November, she called me and said that her period repeats in 20-25 days and she should have period now but she is not having. Can you tell me the reason?...

Wasn't that a safe time to go unprotected?

Me and my boyfriend had unprotected sex on the second to last day of my period, we thought this would be safe as it is highly unlikely to become pregnant at that time. I am now 8 days late, and never usually late, but have been experiencing abdominal cramps for about 4 days on and off as though my period is going to start. Could I be pregnant?...