How do you know when you have completely missed your period??

According to glow I was suppose to start yesterday but my period is always off it could be very late or very early. Right now I am at the point that I knows it's suppose to come and everytime I use the restroom I examine the tp after I wipe to see if I can see any sign of it starting. But nothing... I also checked my cm and it's light and creamy. I'm just confused and IDK how to figure out if I'm late or not ugh...