My girlfriend has been taking Ambien to help her sleep and I have read that Ambien can raise the hcg levels. Her period started on the 9th and ended on the 12th (which is normal for her). We had unprotected sex on the 17th, on the 8th day of her cycle. Given that she is very regular with her period, we believe she ovulated on the 14th day which would be the 23rd (on her 14th day). Given that it would be a full 6 days before ovulation, we believe it was safe. Thing is she took a home pregnancy test on the 27th at night and was negative. Took an ambien and went to sleep. The next morning she took another test and it was positive. Given that it was just 5 days after ovulation, Im guessing it has to be the ambien that raised her hcg levels to rise cause there is no way that in just 5 days after ovulation her levels of hcg could be high enough for a positive. Am I wrong