Only 10 pound weight gain 7 months

So I my doctor noted I just reached the 10 pound weight gain at 7 months and said she will be ordering a growth scan because I haven’t gained any weight. In the beginning I wasn’t gaining any weight at all. Last month I weighed 1 pound more but lost it this month.

Is it normal not to gain much weight ?

I lose weight sometimes by 1 or 2 pounds each time