What am I doing wrong on this afghan???

I'm crocheting an afghan using double and single crochet. It looks like a giant tutu for some reason. like it gets smaller the more I work on it. I started out with 200 chain stitches and I'm alternating a row of double and a row of single. I'm only on row 4, but I don't want to keep going if I'm screwing it up!!! HELP!!!!!!!!!!!!!!