Random attacks where i can't breath?

I'm not sure if I have anxiety or not. I can just be sitting down & I randomly start having trouble breathing! But if I do have anxiety I'm not sure what the reason could be, I'm perfectly fine & nothing is wrong with me, medically . I just had a sports physical a few weeks ago , & everything was perfect. After i got my three shots, in the car i had trouble breathing. My mom said as a child , she had anxiety really bad. I think i just read the symptoms & freaked myself out. But ever since then I've been having these attacks. I was thinking about the reasons , and i used to have bad allergies with cats, dust, and grass. I have tree cats at the moment, but they have never bothered me before. The attacks times vary, they aren't ever long though. I know for a fact they aren't panic attacks , because i have no reason to have one, everything is fine in my life. Nothing traumatizing has happened recently , and i have no memories of the past that could trigger panic attacks. Therefore, nothing has happened traumatizing in my life ... I just need help on finding possibilities on what i may have. Thanks . (: