Eat more or stick with it?

WalkingAlong

I use a scale and a HRM monitor whenever I exercise, even for walks with the dog.

Are you 'eating back' even what your HRM says for dog walks? I wouldn't. Unless you're really moving along and your HR is elevated, the HRM isn't really giving you a good estimate. If you're going miles, maybe use an online calculator. .3 X weight in lbs. per mile is a common rec of net burn (BMR removed). So for you that'd only be like 42 calories per mile. Sad, I know.

Aiming for .5lb loss per week is 250 calories a day. Eating 1550 and eating back makes it really hard to achieve 250 deficits per day because you had better be dead-on in all your estimates-- TDEE, intake, exercise. If you underestimate your intake by 10% (trained loggers usually missed 25%), there's 150 calories of your 250 deficit gone. If you overestimate your exercise by 100, there's the rest. So you may well be eating at maintenance levels now. Though a few weeks of no losses, it's hard to judge from that short a time.

1800 pre-exercise burn (1550+250) sounds like a lot for someone 5'2" and 139lbs. Mine is usually below that and I'm 2" taller and 15lbs. heavier, but probably older.

RHachicho

Sounds like you might be hitting the point at which your body starts saying .. no were not losing any more fat ... we might need it. Our bodies do have that cut off point and it's different for everyone. I suggest giving carb cycling a try. Or working out like a demon.