I've lost weight since hitting menopause -- very gradually (maybe a pound a month) for a total of around 15 pounds at this point. I'm currently at my lowest "natural" adult weight (meaning achieved without consciously restricting any food intake), and I'm still continuing to lose. I'm still about 15 lbs. overweight.
The loss is probably due to several factors, the biggest of which is my hormones settling down!
But I now work a job that is more active and less stressful. Also, while I still have a sweet tooth, I don't binge like I used to (like eating a whole bag of cookies in one day). I've always worked out reasonably consistently, but those workouts are now less intense, which may also have affected my appetite. Now I eat what I want, but try to make healthful choices and I feel satisfied with less.
As long as your energy is good, you are eating enough, and your blood work is okay, I wouldn't worry about it too much.