Not this early and not in veg., its normal the yellowing of leafs and fall off leafs by the middle of flower., if u are getting rust looking spots in bottom leafs and its not the tip of the leaf then its not nute burn., ill bet anything shes root bound and need a bigger pot to stretch het legs., lots of weird looking hard to id start happening with root bound and small pots.. just ma 2 cents toke on ====~~