Losing weight

I’ve been working out, and haven’t been eating that much through out the day. I only eat to fill in the needs of me being hungry, and I have a calorie tracker that I use to track how much I eat. However, I’ve been hitting below my goal calorie rate. I’ve been losing a pound each week, but for the past 2 weeks I’ve stopped at the same weight and I’m not losing anymore. I currently weigh 133 pounds now, but my goal is 123. Ive been working out a lot, so I don’t understand why I’m not dropping anymore. I’m doing everything right? I don’t understand, maybe it’s because it’s muscle building up underneath. But why isn’t the fat burning off yet?! I was supposed to be my goal weight on March 10th... help