20 plus year smoker of at least a pack and a half, closer to 2 and half packs or more the last year or so here. Having only been completely smoke free 3 days and have yet to cough up anything, but my congestion has disappeared. I've smoked Winston's for over 5 years now, which is supposed to have no additives, beyond tobacco. Not sure how true that is because I got pretty sick for a few days when I tried to roll my own with American Spirit Tobacco a few years back, but then again that could have just been the difference in nicotine content. My point being though is WHAT I smoked could have something to do with my experience as well, as I have yet to experience any hacking, or coughing up of any type of mucus and I was wondering when and if that is going to start at some point, so my concern has been sort of the opposite. I did take Mucinex for a few days before and the first couple of days to try and preemptively help in case I did start to, so you may want to try that or save money and just buy some guaifenesen, which is the same thing only much cheaper. Exercising more like someone else suggested is a good idea as well.
On a side note, my lungs hurt the first few days I started vaping, and was smoking at the same time. Much less so though, as in only 5-10 a day at that point. Good luck and hope you stick with it, that should tell you how much junk smoking put in your lungs, and that despite vaping, it is all coming up!