Am I not losing weight because I’m breastfeeding?

I’ve been trying since the beginning of the year to lose about 25-30lbs.

I work out with a personal trainer and health coach five days a week. 3 days of cardio and 2 days of strength training.

I’ve been following a healthy and balanced diet. At first I was restricting calories under 1800. Saw no change so I restricted more down to 1500. Still no change. Then my health coach calculated my TDEE (total daily energy expenditure) and it was 2,500 calories because I am still breastfeeding my almost two year old. So I increased my calories. But instead, I gained weight fairly quickly. Seemed like an entire pound a day!

Like I said, I work out every day and I am extremely active outside of that. I garden, I take care of my two high energy kids, I cook, I clean, I am running around constantly. I never sit down. My Apple Watch says I am burning roughly 800 calories a day.

But I am not losing a single pound. I also don’t think I’m gaining muscle replacing the fat, because my measurements are not changing either.

Is this because I’m still breastfeeding? Are hormones doing all of this? My fitness trainer said he has never seen such a thing, that I’m working out so hard and eating clean that he doesn’t understand why my body isn’t changing at all.