Try bleeding your brakes, and get the fluid up to where it needs to be. Then keep an eye on it. If it gets lower and or the brakes get mushy again, and you cant find any wet spots around the wheels or the master cylinder, it may be a faulty booster.

check around your wheels and look for any brake fluid leaks air is being introduced into your system from somewhere and air compresses and your pedal goes to the floor. if not take to a shop they should be able to find a leak.

An inch under minimum is OK as far as you are concerned? Maybe you should have a technician look at it before you kill someone.

You have a brake wear, need to repair

I drove to school today and was able to come home about a 20 mile round trip and I just tried going out again and usually I can press the brakes down half way to stop my car, now I have to step it to the floor to get it to start slowing down. I checked my fluids and its about 1 inch below the min line. Could this be a leak in the brake booster because there is no noise at all when braking and I don't see any pools from leaks under my car.