No period but negative HPT...now what?

My husband and I are TTC, my December ovulation was supposed to be Dec 6th (according to glow app, I was not measuring with ovulation tests) so we planned baby making activities accordingly.

I usually have a 28-31 day cycle so using that plus glow app, I expected my period on the 19th. No AF that day or any other since...

On Dec 30th (today) I took a First Response hpt which came up as negative. My question is which should I go by more, the fact that AF is not around (yay!) or hpt was negative (boo!)? Should I take another hpt some days later? How many would people suggest? And at what point would it be worth talking to my doctor about late AF and/or asking for a blood test?

Sorry for the barrage of questions, first timer just finding my way. Any suggestion helps, thanks!