Brownish discharge! Help!

​So I'm TTC baby #3. AF is suppose to arrive on 10/2 according to Glow. Not feeling any signs of her. But just went to the bathroom, and noticed some minimal, dryish, brown discharge on my panties. When wipe, nothing on toilet paper. I'm totally cluess as whT to look for. It's been nine years since I had my last son. Feels like I don't know my body anymore, plus my cycles have been very irregular. Can this discharge be a sign of AF or maybe something else????