Is broadcasting the location of Earth to potential extraterrestial civilization regulated? How many times have we broadcast the location of Earth to the outer space? Are there any regulation in doing so?

I know so far we have send the Arecibo Message, and any receiver can trace the message sender's direction by the direction with which the message is received. But have we ever pin point our exact location of the galaxy and send it as a message?
No, except in the sense that national broadcasting and so on is regulated. Our location can be fixed, as you suggest, from simply looking at where the signals come from.

Perhaps, though, you mean is it sent out "regularly" (i.e., at specified intervals). In truth we have been sending very powerful signals continuously into space since the dawn of the television age. Those signals may now start to wane in strength as we move to digital terrestrial television but that won't bother any aliens for some time yet.