Yesterday had first BCG treatment. Instilled bladder OK, no problems holding solution in for 2 hours, I followed advice of some I had read on-line and did not drink much of anything before Dr. appointment. Then late in the afternoon of same day I got to feeling like I had bad cold headache, aches, sore throat, slight fever. Today, I feel better but still, weak, tired and feel like I just got over a long illness. I was told by my Dr. that the effects are cumulative. Does that mean the effects last longer or that they are more severe?