Temp down but missed period?

Hey ladies. So yesterday my temperature dropped by about .20°C and today it dropped another .06°C. My period was due today (I think) because it looks like I ovulated on Sept 24th or cycle day 18, which is usual for me.

Assumed my period was coming since my bbt dropped. Is it possible to be pregnant with a temperature drop like this?

I'm thinking AF will probably come tomorrow but my luteal phase is usually always 14 days, I don't think it's ever been longer.

I was just diagnosed today with unexplained infertility, so feeling a little down and wondering if it's possible I could be pregnant.

My internet cheapie tests have all been negative.