Anyone else experience this?

I have PCOS and have been taking clomid to induce ovulation. I took clomid on CD 5-9 and had a positive ovulation test on CD 26. Based on prior clomid cycles, I should have gotten my period yesterday (Sunday CD 41), but no period. Just some very light brown spotting. I’ve been checking up there this morning and there really isn’t that much brown and no red. TMI, but I usually have bright red blood the morning of my due period, but nothing. I’ve taken pregnancy tests and all come back negative, including this morning with FMU. Anyone else experience this? Could I be pregnant even with negative tests? I plan on calling my OB tomorrow if I still have no period.