Causes Of Pain In Left Side Under Breast With Needle Like Pricking Sensation

hello sir.......im 26yrs.........im havng pain in left side underbreast.......i hav done d testing also 2d echo,ecg,tmt......blood tests,xray.urine test everything its normal..........i hav cough.......few days back i had dust infection so.........and i hav shown for gasterlogoist even he had done endoscopy even dats normal bt if i get tensed n start coughing pain ll b more i feel.........but always i ll b noticing dat pain so im feeling lik dat or wat.........doctor he said its bcoz of gasteric its becoz of left side i am worried.........but heart doctor he has said there is no problem in heart........its becoz u r so much scared u feel pain is more...........but its lik needle priking sentation from underbreast towards back.....