It is not normal at all.
Most smokers that smoke at least 2–3 cigarettes a day smoke more than 2–3 cigarettes a day. It shows at least some form of self-restraint to stop where you’re stopping. So no, it’s not normal.
I have a cousin who I consider to be a non-smoker (since he doesn’t smoke), but sometimes when he’s at a party, he happens to buy a pack of cigarettes in a night shop if he feels like it, smokes some cigarettes (could be 5, could be 10), and then doesn’t touch the opened package for six months on end till “he feels like it again.”
He reminds me of you because he is in total control. The irony is that he is a severe (but still functioning) alcoholic. And when he starts drinking, he virtually never stops.
(One of my best friends is also like that: he smoked 2–3 cigarettes a day for more than a decade and was in constant debate with himself about whether he was a real smoker or not. Nowadays I rarely see him smoke anymore, but he keeps drinking all the same.)
In any case, if there’s a good way of smoking, then I think your way is one of the ways to go (although you might want to consider my cousin’s approach as well). My guess is — not a pulmonologist nor a medical doctor in general, so this is a modest opinion — that on the cancer side your approach might be moderately safe, and the extra upshot is if medical problems would require you to quit sometime in the future, it would be very easy for you to do so.
But (and there’s often a but in this kind of game) —
Researchers are increasingly convinced that even long-term smokers who smoke a low dose per day are at a much higher risk than previously thought (due to the long-term daily exposure to carcinogens). In fact, if we are talking about two patients called Erin and Robert, where Erin has smoked a lot on a daily basis during two decades but Robert smoked only half of what Erin smoked per day during four decades (so that the total amount of consumed cigarettes is the same), then Robert’s prognosis is expected to be worse than Erin’s.
It so happens to be that my aunt Erin smoked 20+ cigarettes a day for about two decades (what a coincidence), and more than 40 years after she quit, she was diagnosed with stage 4 lung cancer after three weeks of persistent coughing (and nothing else). She died in week 4.
And since generically Robert’s case would be even worse, you need to reconsider ASAP and stop smoking altogether —
Enough is enough.