confused

Lena

I haven't started my period and my period was it due a week ago. I'm barely stressing, I do have some stress in my life but not a whole lot and I had a normal period last month and it was right on schedule. I've been taking pregnancy test and they all turned out negative but I also been taking ovulation tests to see if I'm still somewhat ovulating, to see what's wrong and there's a faint line on the ovulation test why is this?