What's happening?

For about four or five days now, i have not been breathing regularly. every so often, and i put emphasis on the word often, i will feel like i am losing air and have to inhale and exhale deeply. i have never really had respiratory problems before, and no one in my family has smoked for about 11 years, so i am not breathing in second-hand smoke. its just, i have many moments where i need to take a deep breath, just to get the feeling of normal breathing back into my lungs. i dont think its serious or anything, at least not right now, but this has never happened to me before, and now it occurs so frequently. (at least every 10 or 15 minutes.) and once it happens, i have to inhale about 2 or 3 times per cycle. its very strange and it feels a little scary when i feel like some of the air is leaving my lungs. i just want to know, has anyone experienced this kind of thing before or does anyone have any ideas what i should do to breath normally again?