Strange BBT

Rachel • TTC #1 - on the 20th cycle as of 3/16. Undergoing fertility treatments since 12/15.
Can anyone make sense of this? OPKs came back positive where it says I should have ovulated. My temp went up and then immediately dropped. I stopped recording because I was on vacation, but my temp stayed way low. Then just a few days before my AF was due it went up again and has kept climbing ever since. I'm now 1 week late with 3 BFNs. I went off Clomid this month so I'm wondering if that completely messed up my cycle or possibly made me O later? AF has still not come. My dr wants me to wait over the weekend and if still nothing to come in for some tests