Generally yes your right. But could be a tapping sound from one of the wheels spinning that you might not hear when sat in the car.
It would most likely look like a buckled bike wheel when it's spinning should see it. And it's the only thing I would say to check now before maybe getting a garage to check the pump, Just to say it is, or isn't
Have to keep us informed might be non of the above. Maybe no more then a blockage not sure I have heard if that's possible but you never know :D