my girlfriend got her last period on august 29,2010 and before that on july 28,2010..we reccently had sexual intercourse on september 27,2010..though we did not use any preventive measures, i am sure i removed my penis before ejaculation. but then she did not gt her period still..she may be pregnant ?? whrn checked online calculators, sep 27th is a day of menstrual period but not fertile period...