Is my scale wrong or am I doing something wrong when it comes to losing body fat?

[RyanEC]

For the last few months I have been trying to get body fat % from 22 to 12.

I have been using a body composition scale that should tell me my weight, fat % and muscle %.

I have done things recently like walking 10k to 20k steps a day, eat only around 1800 calories a day, check macronutrients, go to gym a few days a week, burn on average 3000 calories a day this week.

Instead of the weight going down it seems like the weight fluctuates more then it really should.
Last week I checked and it was 160.6, earlier in the week it shot up to 166, today it was 163.
My muscle % has been around 45% and my fat % has been around 18.

Could this be me retaining too much water weight and the scale mistaking it for fat? Or am I doing something wrong?

[Massageman]

Use only one reading per WEEK, taken at the same time each week. I tend to fluctuate a lot on the weekends, so I would go for a Wednesday if I was "really seriously tracking". Otherwise, your overall trends are going to be masked by the daily or twice-daily ups and downs. You are living at a 1200/calorie a day deficit, which (technically) means that you should lose a bit over two pounds per week (3500 calories = one pound). This is a fast pace of weight loss. You may need to go to a slower pace in the weight loss department. Just because you lose the weight does NOT mean that the body tissue has been transformed in the proportions and amounts that you want!
If you want the MOST accurate weighing, you could always try "water displacement" weighing of body mass, where you are dunked in a tank of water, and the mass of the water displaced is matched against your weight!

[Chazmatazz269]

Your weight will naturally fluctuate. Pay more attention to long term progress and less attention to short term results. If you’re down to 18 from 22, keep doing what you’re doing. You’re winning!
Congratulations and keep up the good work!