Can't keep weight on

So I was supposed to gain 20-25lbs according to my OBGYN. This pregnancy and I am 29 weeks. I eat really healthy and with GD I have been able manage it without insulin. Huge deal as last pregnancy even with my good eating I had horrible fasting numbers.

The issue is I cannot keep any weight on. I keep losing. Last pregnancy this happened too and my doctor made me see a dietician. Dietician told me everything I was doing was great. So I know my choices are good for me and baby.

Just frustrated feeling like I am not doing what baby needs even though I am trying and eating all day long. Anyone else feel like this.