Do i have an allergy?

Hello,

First of all sorry for my english :D I am a 21 year old female, 3 months ago i had flu and after i had bronchitis. then i felt better but after about a month i had again difficulty breathing,chest pains,and dizziness i went and had a chest x-ray it turned out to be bronchitis again with hyperinflation. My doctor gave me some antibiotics. Now after 3 weeks or so i feel fatigue sometime with dizziness with stomach ache and my lungs heart when i cough or when i breath deep sometimes. I had chest x-ray today and everything is normal. P.S. i used to smoke for 4 years but now i quit maybe in a month i had only 2 or 3 cigarettes. Could i have an allergy ( my boyfriend has a dog could this be an allergy for dogs)? or could it be lung cancer ( my x-rays turned out normal could this be lung cancer but it didn't show)? or could this be cause i stopped smoking a month ago and my lungs are still fixing themselves or something like that??? pls help i need some help Thank you