11 Days Late, BFNs! 🙁

I have very regular 27 day cycles, as you can see in the 3rd pic below. Last month was 31 days (AF was 4 days late). Now thos cycle I bought a bbt thermometer and started keeping track (when I started, my Glow chart said my 1st recorded temp was on or after my estimated day of ovulation in a 27 day cycle).

I'm new at taking bbt and reading graphs, so I'm not really sure when I actually ovulated (I wish I had started tracking bbt sooner!), and it's driving me CRAZY because I've never been this late but keep getting BFNs. Granted I have been using the no-name dip strips that came with the bbt thermometer, but I thought pretty much all HPTS are very accurate these days? I mean no faint lines -- nothing at all other than the control line.

I keep hitting "missed my period" in Glow, and it keeps adjusting my graph. Pic 1 is from today (May 16) and pic 2 is same chart from 2 days ago.

WTH?? Is something wrong? 🙁