MBSJ

I hear very slight squeak when I stop or start to accelerate. This doesn't happen all the time and the noise is very slight however I can notice it. I had to pushed the brake pedal real hard yesterday and I was wondering whether this cause this squeak or it was there and I just didn't noticed before. I have 3200 miles on my C230. Anyone experience this? Like I mentioned before it is very slight noise and I don't know where it is comming from. When I go over the bump I do not get this squeak. It happens when the car is trying to come to a complete stop and start to move.