Thank you heybales, for responding.
I don't have any illness. I'm fairly lucky and don't have any chronic conditions or take medication. We have had some dry, warm weather and when the Santa Ana winds kick up my allergies bother me but that is about it.
I checked the Fitbit graphs and they look accurate. I have 15 minute chunks of no activity or very few steps and I have checked while driving to make sure it isn't logging steps and it doesn't. I have a Zip and I actually wear it to sleep on my shirt and it never picks up steps in my sleep. I haven't hopped onto the treadmill and measured the distance though, so perhaps I should do that. My husband helped me measure my stride length a few months back at the end of summer. The Fitbit has my accurate stride length. We did it outside in the driveway.

I use a scale and measure in grams; my meat before cooking, my potatoes before roasting and my yogurt and my cereal, you name it. I still measure out my half-half in the morning and everything else. I pop my milk glass on there and zero it out to get my accurate milk serving. My husband gave me a hard time for measuring my wine, but I do anyway! So if my logging is inaccurate it shouldn't be by much.

I haven't consistently hit my TDEE, I only exceeded this Saturday because we went out to dinner and I didn't eat much to account for that earlier in the day and I typically only eat half of what I get at a restaurant anyway and I have no idea of the calorie count because it wasn't a chain restaurant.

I'm at a loss as to why I'm gaining. As I said the last 38 days my average daily intake has been 1832. Just these last 10 days I have bumped it up to average out to 2000. My Fitbit gives me anywhere from 2300-2600 a day depending on my walking. I confess sometimes I do end up walking a lot in the morning because I take a different way(we have lots of inclines here which are great for varying it up). So in the morning I've walked 10-13k steps just from trekking around the neighborhood. Technically I have a lot of active minutes but the walking is so pleasant it never seems super difficult. I'm fine if my TDEE is actually 2100 that doesn't bother me. What frustrates me is that I log accurately, I haven't hit TDEE consistently and I have been gaining and popping out of my pants. Everything feels tighter. I saw my profile today in a glass door and my stomach didn't look like this earlier in the summer. My back looks the same, some more definition when I flex but nothing earth shattering. My waist is thicker. My thighs seems thicker and my calves are definitely thicker. My workout pants feel tighter. Last year I sprang for the Athleta pants and had them hemmed and they are tighter everywhere and I have spillage at the waist, which I didn't have while pregnant and going through a miscarriage.

I don't mind if my TDEE is very low I guess I just need some advice on nailing it down so I can cut properly.

Thank you everyone.
I understand what you are saying. I never dieted in the past. I lost some weight twice in my life once in my early-mid 20s and then started almost 2 years ago. My parents are anti-diet, if that makes sense. My mom always had whole milk and butter and generously uses olive oil in everything, it's how I grew up, we ate everything and my mom is a phenomenal cook with a crazy metabolism. As I moved out I gained weight because well---take out and soda, to my heart's content and less activity! I lost that weight walking and following a nutritious meal plan that was about 1900 calories a day. Then I had 5 babies in 10 years and kept some weight each time and was inactive and eating too much for my size. So I buckled down and started walking and joined and followed the MFP guidelines, which for my activity level with my walking was probably too low. I think that's what did it.

I'm struggling only because I didn't think I was undereating, although definitely didn't eat enough protein in my deficit which I'm sure caused muscle loss. Then with the plateau and gain with pregnancy and miscarriage I just have been trying to go up to tdee very slowly so I would offset the gains while maintaining my activity level.
I'll visit the doctor for labs although I have no other symptoms that I would think of that point to thyroid issues.
My macros have been great. I nail my protein daily and sometimes struggle with the carbs and fat but I get them in almost perfectly. Even if means slapping some peanut butter on my plate with whole wheat toast and a glass of milk(oh the sacrifice ).

I'm still hanging out eating more, just a wee bit nervous and stressed about it. Trying not to be.
You all are fantastic!