Losing weight while pregnant?

I am in the process of trying to lose some weight. No diet pills or anything like that...just eating right and exercising(walks, runs, light weights, etc.) I am TTC and hoping to get pregnant over the next few months.has anyone been given the OK while pregnant to continue to lose weight as long as it was a decent amount of calories(1500) I am 20lbs over what I was at the beginning of my first pregnant 4 years ago and 5 lbs away from my heaviest point during my pregnancy. I am just curious as to what the doctors would say considering that I am about 25lbs overweight. I do not plan on starving myself or anything crazy like that!