Here's what I've been doing for the last couple years. I keep a Sharpie in my range bag, and whenever I eject a carry round for cleaning, etc., I mark it with a small dot on the back of the case rim. Then I know for sure that round was chambered, and it gets rotated to the bottom of a magazine. If a round gets ejected that already has a dot, it would get a second dot, etc.
Maybe this is paranoid, but it's a simple measure to help avoid setback.
Maybe this is paranoid, but it's a simple measure to help avoid setback.