Your baby will be getting everything it needs from your body. Even if you are losing the weight...baby is still growing. Only one that can tell you if the baby has stopped growing is your doctor when they measure you and the baby....no worries
You really cant but that shows about right.. I am 27 weeks and have gain 14 pounds and i only gain 1lb from 23 weeks until 27 weeks.. I think some weeks you just dont gain as much.