How long do you need to see if "consistency" is working?

mcjabber

How long do you guys give it when you're trying a new tactic?

I've just started experimenting with IIFYM (don't worry, I'm not eating crap all the time, I'm just paying more attention to macros), and playing with my TDEE--so I'm eating the same calories every day regardless of workouts, because the workouts are already factored in. I'm working out (mostly lifting, some cardio) fairly vigorously as well (this is not new for me).

I'm at the beginning of my fourth week eating this way, and frankly, it has not been good news. So I'm just wondering if I should stick it out and expect results from even MORE consistency, or if 3 weeks is enough of a try to determine it's not for me?

EDIT: The first week I lost a few lbs, the second week I gained them all back, the third week I lost 1, this morning I was up 2. SO... I'm pretty discouraged at everything. And my body fat has remained the same.