Okay, well a phyisotherapist here in only like $40/hr (Canadian) however, wouldn't remotly know how much it would be to see one where you live. What a pysiotherapist will often do is a posture test to see if your shoulders are retracted, protracted, pelvic tilt, and even shoulder tilt etc. He/she will often give advice on how to correct these problems to see if the corrections will "cure" your problems you are having.
My nonprofessional advice if you experience this problem once a month or less is just to keep doing what you are doing but avoid however you aggravate it.
If you can do one test for me is; stand straight how you normaly do with arms relaxed to the sides, now look down at both hands. You want to see only two knuckles (1st and 2nd) visible. Seeing the two listed will ensure neutral position of your shoulders. Seeing more than two will indicate tight chest and or weak back and for seeing less than two.