Ibuprufen will actually cause an attack if you have asthma, I cannot use it, even the gel makes my chest bad. It won’t kill you or anything, so if you try it and it helps then you probably don’t have asthma.
I also run using a buff, but rarely cover my mouth. I just make sure I have salbutomol with me and take a blast if I feel my breathing getting bad.
Also, salbutomol will help your breathing regardless if you have asthma or not. GPs have a high tendency to write patients off as having asthma when they don’t. Both my kids were diagnosed and given medication, but neither turned out to have asthma.