you're probably feeding some flowering nutes now?
ideally, you want to keep feeding it those nutes, with a bit of some extra nitrogen from some source
sounds like you might add some of what you mentioned to your next feeding
you dont need as much nitrogen in the flowering phase you want phosphorus. it the older larger fan leaves begin to yellow its ok as long as the new shoots and leaves arent yellowing. the plant is sending all its energy to the flowers instead of leaf growth which is the primary use for nitrogen
