Because they try to keep you as close to a 3-month interval as possible for cysto check-ups, after the first 6 weeks of BCG the cysto would in fact be about 6 weeks later. When you get to the maintenance BCG, which is 3 weeks long, the next re-check would be approx. 9 weeks after the end of the 3 weeks BCG. The re-check cysto also has to be timed with the next BCG in mind, as they like to wait at least a week between the cysto and the next round of BCG. It sounds confusing, but now that I'm into it I think I have the hang of what's happening in terms of timing. (So far I've had the 6 weeks BCG, last August-Sept., recheck in December, 3 weeks maintenance January, now scheduled for a recheck around April 1, then a week after that another 3 weeks maintenance.)
Small TA Grade 1, May-06; recur (2 tiny), same, June-08; TURBTs both times. BCG begun July-08, dosage to 1/3rd May-10, completed treatment December-11. All clear since 2008.