19 weeks same weight?

Mary898
I am almost 19 weeks and haven't gain any weight since beginning of my pregnancy. I didn't lose weight and never vomitted too. 
I am 5'8 and 124 lbs and started to worry about my baby. 
My diet is super healthy, I eat eggs, veggies, meat and fish. I am just careful about refined sugar/fastfood and carbs. I get my sugar from fruits. I also get my multivitamin everyday.
I know gaining too much weight is not healthy either but I still worry if she is really developing. Do you think is it normal?