In my humble experience, it's not what you do on any one day, but what you do day after day, or at least frequently, that makes the difference. So, dropping your calories low for one day may not do anything at all, or your weight could go down, or your weight could go up!
Try for consistency. I don't mean exactly the same number of calories every day--but I do mean not letting the variation get too wide. In other words, if your target is 1300 (which seems a bit low for someone your size who is actively exercising), try to stay close to that. Rather than, say, eating 1000 calories one day and 1600 cals the next. Some folks find this sort of zooming works for them--for me, all it seems to do is stall weight loss.
Just some ideas! Congratulations on your loss so far!
Jay