My cycle has been off this month, on the 14th my husband and I had sex (he did cum in me, we are not trying for a baby. My cycle has been really regular lately and we expected my period to come on the 17). The next day I had ovulation spotting, which I do get pretty much every cycle), except on the 29th I had an LH surge and I took that as my period coming but there is still no sign of her. The 30th was the last time I tested with FMU and it was negative. Am I in the clear if I received a negative 16 days after sex?