I too had something that I now realize had the symptoms of mild Covid earlier this year. The symptoms included fluid (felt like water) running down into my lungs, something that I have never before experienced in my life!
I remember coughing in vain to try to relieve/remove it, and wondering what on earth could be causing it.
With hindsight, I was extremely lucky that this didn't turn to pneumonia, but it was before Covid was officially in this country, or at least before anyone who hadn't travelled to China was known to have had it, and as it remained mild, it never crossed my mind at the time that it could be more than just a nasry cold, albeit one with a symptom I've never had before!.
Don't suppose it could have been Covid because of the timing, unless it has been here longer than they think, but if I got the same thing now, I would certainly think I had it!