I know in my experience that false negative pregnancy tests do exist. Myself, my daughter and my daughter in law had to wait until 3 weeks past missed period to finally get a positive on the urine pregnancy test. It dont matter if it says 4 days before missed period or not, it still may be a false negative. We know from experience. So if you still have not got a positive up until 5 weeks past ovulation or 7 weeks since last period--do not give up hope. There are also women known to never get a positive on a pregnancy test. Not so common--but it does happen. If still in doubt go to the .Dr and get a blood test. If you still have neg at 7 weeks past last period--i would def go to .Dr in case it is something else you are experiencing.