I'm not really sold on vegetarianism - unless you pay particular attention to everything you eat, there are quite a few nutrients you could be short on; these include calcium, vitamin B12, selenium, etc. Meat, dairy and eggs are the best sources of these nutrients.
In addition, keep in mind that you DO need some fatty foods - the monounsaturated fats (MUFA) are essential to good health, and can also help you lose weight. These come from things such as avocados, olive oil, coconut oil, nuts, seeds, etc.
We are all different, and you've done an excellent job of losing. I do agree that you might be better off to have a target weight, rather than a target size - don't forget that clothing is sized different, depending on the manufacturer; therefore, you might not always be able to fit into the same size. I'd hate to see trying to lose more weight than you need to, simply because you targeted a too small size for your body structure.
thnks for the comments on my improvement. I have worked hard i was a size 15 on junior pants and now im a 7!. i did vegetarianism, and its one of the ways you can kinda get into lean eating habits, because basically 90! of fatty foods are not vegetarian. and working out is the best i could have done so far, its been 2 years now!
At 5'9", you aren't really overweight unless you have a very small frame.
The first thought that comes to my mind is that you aren't taking in enough calories, and with the excessive exercise, your body has gone into starvation mode, in which it hangs onto the fat you already have because it thinks you aren't providing enough food.
Your basic metabolic rate - the number of calories needed for your body to perform basic functions (heart, kidney, digestive, lung functions, etc) is 1593.65. That means 1200-1300 calories/day is not enough to keep you going.
I'm 5' 10" and 215lbs. I've lost 10lbs so far, and am currently a size 16 (I think... I haven't bought clothes in a while). Congrats on your loss so far, and the switch to vegetarianism must have been difficult. I have no suggestions for what else you can do to lose weight other than maybe switching up your exercise so your body isn't expecting the new/different activity. Sometimes we get used to something and it stops working for our bodies... At least that's what I have been told.
I also have to say that at our height, I think a size 3 is a bit drastic. I would love to be a size 7. I would suggest setting a goal weight rather than a goal size.
Sorry I'm not more help!
Wow! Congrats on such a big improvement! It sounds like you're working very hard and you definitely deserve the body you're after. It's normal to lose rapidly in the beginning and then slow down little by little, but as long as you keep your workouts varied and your diet lean, you WILL get where you want to be. (Although I must say, size 3 while being 5'9 is setting the bar quite high! Just be careful.)
In this 1200-1300 calorie diet, what are you consuming?