Im not losing any weight in the abs area?

i started dieting and exercising 2 months ago and have lost 15 pounds. i am now 120 pounds at 5'6". i use an elliptical for 30 minutes six days a week. however i dont seem to be losing any weight around the abdominal area which is the most problematic area for me. should i start doing abs, or would that make my waist look bigger. help please.....