Is Hormone Pill Recommended During Pregnancy?

I cant lose weight. When I was pregnant with both my kids the doctor put me on a hormone pill. With my first child I lost 28 pounds and with my second I lost 41pounds. After I had them I went right back to the same weight. I dont gain weight, but at the same time I cant seem to lose it either. What should I do? I am tired of being fat. I excercise everyday and try to eat right.