Advice: Period No Show BUT not Pregnant!

Nikki
Hey Ladies, 
I need some advise, I've been tracking my period using glow for some months and now it predicted that my next expected period should have started Saturday just gone, well it's now Tuesday and still nothing. 
I've done a pregnancy test (digital & none digital) and they both came back negative. 
I've had some pains like it was coming and sore breasts  but still no show. 
I'm not sure if I should leave it for a few days and see what happens and then go doctors or what.