Well...if you're rarin' to go and feelin' good I guess you and go ahead and do one again! Most people wait 2 weeks or so...but if you're getting results, you're getting results!
Most people flush until they're stone free. That can take anywhere from 7 to 20 flushes depending on the person. Southern Belle flushed all her stones out (after 8 or 9?) and I feel like I'm getting close...only got 16 out last time.