I need some advise please!!

Andrea
I've been on clomid for 5 months now and since I have started my periods come right on schedule my cycle is 28 days it hasn't been late once since starting. This month I had 4 days in a row that I received positive opks and I should've started my period yesterday. She didn't show so of course my husband and I go out and buy a few pregnancy tests first thing this morning I take one but its a BFN. Since I ovulated 4 days this month I'm not entirely sure how my dpo I am and I checku temp but I missed a few
days which was around the time I was getting my positive opks. Just need a little advise is there a possibility I could be pregnant and it's just too early to pick up on a test???