DJ 1601 Rattle Question

[ade06]

I was playing with my son the other day and I guess I shook or bumped my watch too hard. I now can hear a slight rattle in the watch (like something is loose). My watch is still keeping good time. Does anyone know what might have happened and what I can expect to pay to get it fixed. Also, if I don't get it fixed in the near future (since the watch is still keeping good time), would my continued use of the watch have any long term effects to the movement?

Thanks in advance!