bearo,
I sure believe your stone story. I had one that was about that size. I do not know how it came out but it did. I still have the thing in my freezer ! *LOL*
Yes it did come from your gall bladder.
It is recommended to wait two or three weeks to give more stones time to move forward so they can come out. Also, your body needs to rest and recuperate from your knife-less "surgery".
However.....there are people that have done it more often than two weeks. I guess it is really up to you.