About 1-2 times a week I get a stabbing pain in my left side under breast. It can be severe enough to not breath but only for maybe 10 secs. Normal?

Normal? No. While such a pain is not "normal", it is unlikely to be anything serious. Many pains like this simply pass with time and simple anti-inflammatories (aspirin, ibuprofen, naproxen, acetaminophen) are worth a try. Signs that it should be looked into further include worsening frequency or intensity, associated cough, fever, shortness of breath, masses or swelling in breasts, local skin changes, etc.
NOT norma.l. Not normal. Can be as simple as a strained rib muscle or serious like a cardiac problem or breast issues. Please see a primary md.