SO, for all those waiting for the answer, the answer is simply: Don't know yet. I went in a took some more tests today, and my EKG and blood pressure are amazing. Everything else, not so much. My doctor sent me to this other clinic where I was supposed to get a chest x-ray, and then it turned out they didn't even have an x-ray machine. I was pissed. So then I went to another doctor and had blood taken. I'll get the results for those in a couple of days.
Then I went back to my family physician and she told me that it could be an infection of the cartilage in my rib cage, which is common in growing boys, but since I'm 21, I'm probably not growing anymore. So she said it is probably not that. So then I'm thinking "WTF? Why did you just say it could be this, but it's probably not".
So the bottom line is, she gave me a pain prescription an I have to go to another clinic to get a chest x-ray tomorrow. Once we have the results of the chest x-ray and the blood work, then we'll know what it is. Until then, today was a waste of time, gas, and money.