What is a way that I can check my body fat percentage without any tools or going to the doctor; basically I would like it to be simple enough for me to do it in my room.

The only tool you need is a paper measuring tape... if you don't have one you could always take a string or something and mark if off by inches.. once you have one of those there are several websites that will tell you exactly what to do... measure your neck and waist... etc etc.. Here are some links..
Calculate Your Body Fat Percentage

Body Fat Calculator

Both of those sites will at least give you a general idea!

How am I supposed to use the string to calculate my body fat percentage? Never mind stupid question. Thanks a million.