Hey Ethan, how are you? The phrasal verb ''work into'' should not befit your context as much as you would expect it to. Rather, ''work on'' sounds a better idiom to be used in this case. ''Work on'' is used to convey the idea that one is exerting themselves physically or mentally in order to do, make, or accomplish something. As regards the case you provided, it would mean that you have not yet put your plan into action, and thus you are still making an effort to do so. ''How is your plan going?'' - Oh, I am still working on it!'' Hope that helps!!! :)

You could also say, "It is still in the planning stage". Another common expression is, "It's early days yet!"

"I am working on it." Use "on", not "into". Another option: "I am working up to it." Which has a meaning like you are still approaching it or preparing to start.