No, it will get worse. You should always fix any nutrient problems before starting flower. Flowering nutes have very low N. You have to withhold N to get the plant to flower properly, but it still can use nitrogen. The leaves may yellow towards the end of flowering, but growers who have their feeding program really dialed in do not have this problem. The final repotting when you are going to start flower should include some rich organic material that the plant can slowly use.