I might be late?

I think I might be late, but I don't know for sure. My periods are very regular, like clock work, I can count on it to come on the day the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> says it will. But last month it came two days earlier (it was supposed to start Sunday but started Friday).

Now because it came earlier last month this months period was supposed to start yesterday (Friday), and it never did.... I don't know what to think right now 😖

I know I should wait to see what tomorrow brings but I guess I just want other women's thoughts