Me and my girlfriend had sex nov 20, 2017 and i expect that she will have her period dec 07,2017 but it didnt. First i used some protection and last is i tried not to use protection(condom). It was kinda rough but not that too rough. She used 2 pregnancy test in same day but different time and it was january 4, 2018. And it shows negative and she didnt have symptoms at all. Pls help me quick. Thankyou!