Here is a great link to look at where the weight goes. There is so much to weight gain in pregnancy. At 15 weeks, my doctor told me an average of 5-10 pounds at that point is normal. Very little weight gain in Tri1, 1/3 of your weight in Tri2, and 2/3 of weight gain in Tri3. I hope this helps!
(& yes, I know what you're feeling!!!)