Please help ASAP!

Glow said my period was supposed to start today. Usually Glow is off by a day or two. But last night, I had very light spotting. Brown and pinkish. I get it before my period. So I went ahead and put in a tampon. When I woke up this morning, there was no blood. Just the same spotting from last night. And throughout today, I am still getting a tiny amount of it. I'm worried. Does anyone know what brown and pinkish cm means? Do I need to be freaking out?