Help!!

I think I might be pregnant but I don't want to test too soon. Glow says my period is due in 4 days. I've had it come 3 days earlier and 2 days later, and right on time, from glows predictions. Last week I had clear mucus with a tint of red.. it was very odd to me. A couple days ago, I had just a tiny bit of blood. Now it's like brown and very light. There when I wipe, but not a lot at all. Could this be implantation bleeding? Or my period? I'm very confused and want to test. Just want to make sure I'm testing at an okay time.