get a test or no?

Savannah
I've been using 2 period apps, one called period tracker and then just now glow. my old app (I've logged in it since last September) says I'm 5 days late and it's always been pretty spot on. I logged all my things into glow and it says that I shouldn't get my period until Monday. debating if I should go and buy a test or not? what do you think ladies? 
and then glow.