Do you have a pic.....if it's not severe, I wouldn't flush. Flushing is stressful to the plant and it compacts the soil. Imo, it would be better to just water the next couple with straight water to fix the issue.
It's normal to use high nitrogen nutes all the way through week 3 and some people even advocate high nitrogen feedings during the entire flowering period, so it's not the end of the world. So again unless it's severe, I would just continue as you were and just lay off the nitro for a few days.