Gaining weight when exercising more

Just an update on a post I wrote last week. Everytime I bump up my exercise I gain weight....well it's one week later. I went back to regular logging on mfp and saw places I would indulge (only at night and a bit when eating at a restaurant) and I dialed back a bit. But I also dialed back my exercise doing yoga 3 times last week but not walking as much. So I did about half as much as the prior week in which I gained 6 pounds. The result - down 3 pounds. Thanks for your support.
More details:
Current weight 210 height 5'7" female obv.
Tdee 2500 (without exercise) 2800 - 3400 (with exercise)
Cals in daily 1725 to 1800
Total loss this week 3.4 lbs