1.021 sounds a bit high to me also, seems to me it should have been in the low to mid teens. But if it's in the bottle, it's in the bottle. Relax, and wait it out. from your gravity numbers it works out to about 3.5 % ABV. I'm on 10 brews in myself, it's a learning process, and this is a great place to find answers. Hope it turns out great.