i'd go back to the docs. better to get it checked out again
i got the flu in august 2006, was left with a hellish cough where i couldn't string a sentence together without coughing. couldn't breath and felt terrible. i waited a month to see if it would go away and it didn't so went to the docs. they didn't believe me. it took months and lots of appointments till one doctor done tests, but by that time my face was swelling up with infections, i was getting loads of random things wrong with me. then it turned out i had a chest infection, then bronchitis.
i'm now living in a different area and still going for tests now and it looks like i've had whooping cough. but its gone un-diagnosed for nearly 3 years. but its taken my new doctor just a couple of months to find that out where my last doctors it was 2 years
so i would definately go to your docs and ask for tests.