When to test...

So I've been TTC for over a year and a half now with no luck. I have very regular periods, I've never missed a single one. I also know my body very well and I can tell when I ovulate and when I'm about to start my period. Well I've been using this glow app for 3 months now. And it's always spot on for when I start my period but not this time. I'm two days late and I've never been late ever before. I've attached a photo of this month.

My question is, when should I test? I am beyond anxious and can't stop thinking about if this is actually it or if I'm just over thinking. Should I test tomorrow morning? Part of me doesn't want to test and just get another negative and be heartbroken again. Not sure if I can handle this again...