DOMS seems pretty random to me. I don't see it as a real indication of whether a workout "did anything" or not. The best indication is if you can do more than you could before, if your capabilities are improving. I.e. you can climb that mountain more easily, you can hike/run/bike 20 miles today when 15 used to kill you, or weight you couldn't lift before is now a warm-up weight.
Female, 5'3", 48, Starting weight: 163lbs. Current weight: 135.
Starting bench press: 30lbs. Current bench press: 75lbs.