Me and my fiancé are neither trying nor preventing. According to my period stats in this app we had sex several times around when I would have been ovulating. I was due to start yesterday and I normally have PMS symptoms that didn't pop up this time. I picked up a Rexall pregnancy test but when I took it out of the package this morning the blue "negative" line was already there. Should I consider this one a dud and test with a different test?