Intense Chest Pain

I am 53 yrs old and was diagnosed with asthma about 9 years ago. I've always had seasonal allergies since I was a kid.

I am on Advair 500 / 50, Combivent (rescue), Duoneb (nebulizer), Spiriva, and Theophylline for my asthma. I am on Accolate and Zyrtec for my allergies.

I have recently being experiencing intense chest pain especially after walking for 30 minutes or so such as going to the store. I will use the nebulizer (Duoneb) and the pain subsides but is still a bit achey. The other day I had three episodes of pain, within 4 hours, across the full length of my chest like someone had hit me with a switch. The first time was more intense than the last time.

At what point should I see medical attention (including going to the emergency room)? If I went everything I had a chest pain I'd go two or three times a week.