Working off 3 or 4 pounds per week healthy?!

Working off 3 or 4 pounds per week healthy?

I'm currently around 190 pounds, 15 years old. I look a bit chubby, and I want to work off some of my chubbiness. I heard losing 2 pounds per week is healthy, but I want to be at least 160 or less before school starts (in two months). So I'm wondering if losing 3 or 4 pounds per month is still healthy enough. What are the pros/cons?

2 weeks ago
3 or 4 pounds per week** (i put a typo above saying month instead of week...)

You must burn 3,500 calories more than you eat to lose one pound. It will be very difficult to lose that much weight in one week. Three pounds is pushing it on the healthiness issue. Be careful not to over exert yourself nor to starve yoursef.