At your weight, losing more than 1lb per week is likely to be a combination of both fat and muscle, which you don't want. Someone who is obese or more often, morbidly obese, can create a larger calorie deficit and see loss quite rapidly in the beginning.
At 6 weeks, you are doing just fine. With a calorie count that is just below maintenance, it can often take 4-6 weeks to see any sort of change, if you are still preserving muscle while losing fat.
In other words - you are doing just great