Hi all. So I've been maintaining at 112 lbs while eating 2100 cals a day for a while now. I've been training with my trainer and lifting heavier 2 times per week and running 2 times a week. The fifth day I either strength train or run depending on how I'm feeling. I stopped tracking around the 28th since hubby and I were going on a get away for a few days. We stayed active, didn't do anything TOO crazy (ok...we did eat a good bit of carbs/dairy/wine/chocolate but not THAT much). I came back to tracking on the 1st with 3 lbs of gain and a solid inch of bloat/fluff on my midsection. Usually by now the fluff would have gone away but it hasn't!! Do I need to drop my calories for a while? Trainer isn't keen on this idea as she's worried I might have a higher TDEE than I think I do and therefore might be in a bigger deficit than I think. Should I invest in a FitBit to find out my true TDEE? I wonder if it's the opposite and I have my cals set too high? I just don't know. I feel a little lost right now and do NOT like the way I'm feeling. My stomach feels/looks bloated all the time. I have my carbs/fats/protein set at 30/30/40 if that helps.

Any suggestions or experience you'd like to share with me? I'm all ears!!!

If you gained that fast eating extra carbs/food, it means your normal eating level isn't replenishing your glucose stores.
Now, that's probably only accounting for 1 lb of gain there, that's 500 cal worth of glucose and water stored. Rest is probably sodium difference. Which will eventually drop too.

So either tad more carbs, or more food in general, probably is a good idea.

Since at maintenance or under, protein is probably set too high now, so probably room for more carbs. No need always being in semi-depleted state.
Protein only needs to be 1 g per lb of LBM.

You can also increase calories by about 100 and see what happens. If still some glucose to top off, you'll gain some more.