I only sent one money order. Granted, it took over 6 months since sending the money order before I finally had something to show for it, but I only sent one.
I would not recommend sending any others. Contact the institution you purchased the money order from and ask them to tell you when and where it was cashed. Personally, I purchased the international money order from the post office. They were able to track it for me (for a fee, of course).