Hey there, and
At your starting weight, it may have been a bit too much, too fast to go to 1200-1300 calories. Some people find they just can't lose at intake that far below their BMR. Any reason you decided to go that low?
Second, how long have you been at the same weight. The scale, unfortunately, fluctuates - new exercise programs, hormones, too much sodium - all can result in water retention, which will show up on the scale, even though you're losing fat. A week or so at the same weight isn't necessarily a troublesome sign.
Third, what sorts of foods are you eating? Some people find that they only lose if they're getting adequate protein/nutrition/etc. Maybe you can give us a sample day so we can see what you're consuming.