I didn't get much out on my first few flushes (though did see a few tiny pea-sized stones), it was #3 or #4 when the motherload hit. I got pretty sick with that one, too.
I wonder if one month of prep might have dissolved everything..... Doubtful, but I would at least try a few more flushes in the coming months. I've done about 12 of them, my last one was over a year ago, and I stopped because the previous 3 didn't produce anything besides bloating for days (I think next time I'd cut back on the epsoms), so I thought it was time to move on to gentler, more supportive methods for the time being.
I know it's discouraging to put yourself through that and not get the results as a reward and incentive to keep going. I wonder if some massage or castor oil packs over the liver would help as well?