How do you know..?

How do you know if it's your period returning? Just had a surprise when I wiped and it looks similar to how I used to discover my period. How will I know if it's actually my period coming back? Will it be the same as it used to, lighter, heavier??? I didn't expect this at all, I thought I still had time! 9.5 weeks and we're still EP and haven't had a dip in supply or cramps or any signs at all that this would be coming! Not that I've ever enjoyed bleeding from my crotch on a monthly basis but I kinda hope it is returning so it can get regular and we can use the calendar method of birth control again.