Sound from Rear Wheels when Jacking up

Hi All, yesterday when I jacked up my car to switch to winter tires I hear this clicking sound, every stroke I turned the jack it will make that sound and it continues until my wheel is off the ground then it will stop. It only came from the rear 2 wheels and it happened when I jacked up the front and the back (more noticeable when jacking up the back).

I continue anyway, but today when I am driving down a parking lot (down hill turning) I hear this bumping sound from the back (sounds like bouncing basketball), it will go away if I stop but continues once I start driving again. I stop the car on flat ground and examined the tires and found nothing odd. Then when I restart the car the sound went away.

Would be great if anyone can provide some insight?

 

The clicking sounds come from both side of the wheel though (even before I switch them) so I am not sure if it's even related to the thumping sound. Another characteristic of the sound is it sounded in pairs (like bump bump.... bump bump.... bump bump.. ), should I take it to the shop?