My front left brake pad wore out and I didn't even notice until it was far gone. Scary I know. But the rotor got a little chewed up but it really isn't that bad just a few little grooves. Can I get by with just replacing the pads? because I already have that on order. Or do I need to go ahead and get the rotor? I am guessing what could happen is a little shaking when braking if the rotor is too bad. Any answers for this newb question?