Contracting pain in chest

I am 42 and I am a smoker, I know this is gonna sound stange but it is the only way for me to explain it, I have been having some pains in my chest, and they feel like contractions, (like you have when you are in labor) its like it squeezes and then releases like there is something my heart is trying to pass and there is not enough room for it to get through, It is not something that is constant but when it happens it will take my breath away it is so painful, and it will do this like for several minutes and then it is like it gives up and if I walk or do anything while this is going on it only gets worse, sometimes I caught myself trying to breath through it, I can sit down and it does not get worse but it does not let up and this can happen several tiimes a day and sometimes it wake me in my sleep, sometimes my stomach will cramp also, sometimes I will have a pain go down my leg, sometimes there is pain in my right shoulder, sometimes there is a burning feeling in between my shoulder blades. Is this something that needs checked out or is it just stress. Thanks so much in advance.