Didn't ovulate, and I'm late. Could I be pregnant?!

Alexandria
During my fertile week I take home ovulation predictor tests every day until the ovulation test comes up positive. I ovulate every month and it's always on schedule. On July 29th my doctor ran a bunch of test to figure out why I'm not getting pregnant. According to the blood work on that day I was not pregnant. This month during my fertile week I did not ovulate at all. This caused my predicted period start date (in the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a>) to get pushed back. I should have started my period originally last Wednesday (August 19th). According to the pushed back date I should have started yesterday(August 23rd) I don't feel my normal PMS symptoms and my CM is a lot different than normal. I took a pregnancy test last night and this morning but they both came back negative. Could I be pregnant? Or is it too soon to tell? Has anyone else had this problem?