Late period???

I’m usually like clock work with my period. Always have been. Before and after my first baby. I had my last period that started 12/17, according the App and my calculations around 1/1 I was ovulating. We Had sex every other day including on 1/1. I was supposed to get my period 1/15, still no sign of it. I don’t even feel my usual “my period is coming” symptoms but my pregnancy test on 1/16 and then today (1/19) are both negative. Should I just keep taking tests until is shows up?? I’m just so confused how I’m so regular and then this. With my first baby we got pregnant the first month we tried and took a test two days after my missed period and when my pee hit the stick it instantly turned positive, I know every time is different but I’m going insane on just waiting for my period.... just had to share and get it off my chest and I figure the minute I post it or talk about it my period will come.....