So upset they told me I had gestational diabetes and I did not have it

What a load of crap. I failed 1 hour and 3 hour barely. I found out at 32 weeks. I followed the diet, blood sugar readings always came back low. 
Did everything they told me to. Gave birth at 38 weeks to a small 5 pound 8 ounce baby. She's really small for a 38 week old baby. She has to wear preemie clothes. 
My other 2 pregnancies made it to 41 weeks and weighed 8 pounds about. 
I'm so upset she's so tiny. I feel like I starved her and she came early from the very low carb and exercising.