I'm allowing for 3,000 active cases in mid-November in Wuhan. It is expected that "patient zero" was closer to September, and I'm aware of the evidence from WHO and the genetic "dating" that leads to September/October timeframes for when it emerged.
That still doesn't get it all over Shanghai by mid-November.
And if there were more than 3,000 cases in mid-November the problem with the way the virus doubles every 3 days and kills about 1% (particularly before we knew anything about it) is that if you increase that number then you wind up with bodies stacking up way too high.
And now if you assume that there was more than cryptic spread in literally a handful of people in Shanghai in mid-November then by mid-January it would have been slaughtering people in Shanghai in a way that couldn't have been hidden, and Shanghai would have looked like Wuhan wound up looking.
And taking 3,000 active cases in Wuhan in mid-November you get 3,000,000 cases in mid-December after exponential growth, which is 35% of the population which is way over the 7% seroprevalence in April 2020.
Once this virus really gets going it doesn't hide. It can only be around in a population for about 2 months before the bodies really stack up and you cannot miss it (it was probably around Wuhan a bit longer than 2 months without detection because the progenitor virus strain was less well adapted).
In mid-November there could have only been cryptic spread around Wuhan. That means that maybe at the outside 3,000 people around Wuhan had the virus at that point (which I'm likely being generous with that number). Your chances of having contracted it in Shanghai is low. 3,000 people sounds like a lot but China has a population of 1.4 billion people. Your odds are 1-in-500,000 -- and they're much lower given the geographical separation from Wuhan to Shanghai.
You had a cold which developed into bronchitis.
Now if you told me it was mid-January and that you lost your sense of smell so completely that you couldn't smell food burning on the stove and when it came back meat taste rancid, I'd agree you probably had it.