If it's pretty constant while breaking, then it is that your pad needs replaced. You do need to do it ass soon as possible. Safety of course is an issue, but also driving it like that screws up your rotors, a little and your can turn the rotors, depends on the width of the rotor wether it can be done or not. If you can't turn it, then you will have to get a new rotor along with the break pad. So, as with everything thing else on a car, when you think something is wrong you gotta be as quick as you can to fix it. Sounds like you understand that already, and I can understand not wanting to get ripped off.