Are the pads new? If so, that is totally normal. Alot of times there is sediment, or the edges are not chamfered which causes the sparks upon bed-in. Either way, I wouldn't worry about it.
I've done a bed-in before many times on track pads with non-chamfered edges and it's a spark show at 10pm at night
Is it making a loud grinding noise, or does it sound normal?
Chamfered:
Non-chamfered (which is what you may have)
