im 18, 235 pounds 5"10

For about the last 3 weeks ive had this stinging/discomfort in the left side of my chest near my breast bone, I went to the doctor, and she said that my heart and lungs sounded good,

Sometimes when im laying down, i get a weezing type of sound when im breathing but when i cough it goes away,

Right now it also seems like i have a cold ( running nose, stuffy nose, sneezing, itchy eyes) so im hoping SOME of these symptoms could be from that

She sent me for an Xray and bloodwork

What could it be? Can they Tell If there is heart problems by xrays and bloodwork?

It doesn't sound at all like a heart problem.
No, an X-ray and bloodwork won't shed any light on your heart problem but the X-ray might show up some lung congestion.