IMO 20/4 is much better for Veg. As far as your he/she plant, are there any other plants flowering and already budding or shooting pistils? If so they might of been pollenated, check those plants for bannana leaves. I would also recommend you cut off air circulation and clean out the grow room with some hot water and a little bleach. Hope that helps.
I would also recommend you dont cut any leaves or branches off any plants unless they are dead. If it doesnt come off with a little tug, leave it alone. Mother nature doesnt trim off leaves to get more light through....
Peace

BKB