Baby not gaining weight?

Hunter

I've been having weekly ultra sounds the past 3 weeks because my fluids are borderline low, and I had one at exactly 38 weeks and today at 39+1 and within those 8 days she didn't grow at all? I know ultra sound estimates can be off but she measured 36w4d both times and 6lbs10oz exactly. My fluid levels are at a 7 which is lower than last week, but is it normal she didn't even gain an ounce ?