Had about 7-8 within few mins after a shouting match with my male brittany (lol). Too much exertion on the lung maybe. Has not happened again and it’s been about 3 hrs.
That's a good sign then, its only happened the once and not for 3 hours since 
Do you have COPD?
Stress could have been the cause.
Best check in with your doctor if this happens again to be sure there is nothing amiss.
The dr believes it is. I go this Tuesday and do my testing.