Since I had been vaping from the 13th December through to the 31st, I caught a nasty cold and could not use my mod, so hence I bought some cigarettes as I wanted my nic fix, but after having a few puffs from my first one I started to have a coughing fit and also vomiting into the kitchen sink, this was gunk that I had in my throat or lungs over time. The end result was that I had cleared some of my gunk out that was getting absorbed by my juice and when heat activated it, it came out.
Now I do not know if that will happen to you or has.
Then on the 1st January I continued to vape for a few days then went back to the cigs and this happened like such, out of the 7 days of the week I smoked 3 days (Sunday to Tuesday). This happened all month and now as we are in February I have come to the conclusion that I will undertake this month cig free and try an continue from there.