Before I got my ears pierced, there had been something inside my left ear. From outside, everything looked normal, but when you touched it, you could feel there was something hard inside. Now after my ears were pierced, the thing inside my left ear "moved" to the place where exactily the pierced place was. I am worried now.
I will see the doctor tomorrow. But, very very afraid now.

It could be dried wax, and that can move a bit.
But yes, a doctor would be able to confirm that it is wax and not something else that has gone into your ear by some means!

Relax, don't get all tensed up.
And take care that the piercings do not get infected!