Share '20 weeks pregnant, gained 3 lb so far'

Hi, I am 39 and in my 1st pregnancy. I have only gained a total of 3 lb and I am now in my 20th week. I  started at 128 lb, 5'9" and now weigh 131 lb. Comments? I am athletic and eating healthy foods. I can feel the baby move and was negative on the Pentascreen (a good thing)and baby has a strong heartbeat. Otherwise, I am healthy.