Pleural Effusion - 1259175

A few weeks ago I started having very bad shoulder pain brought on by nothing at all. My uncle died of lung cancer after being treated for a shoulder problem that really was lung cancer. So, I knew that the shoulder may be a sign of lung cancer.
I am VERY proactive, so I immediately set the wheels in motion. I had the following done:
two chest x rays (I was told both were clear)
One shoulder x ray (clear)
One chest CT scan (clear)

I am still feeling pretty down and out, and I was thinking how I never SAW my x rays or scan. So I called the hospital and set up a time to pick up the actual reports and talk to a doctor.

ummm.....yeah, my x ray was NOT clear as they had told me. This is what it says: "....a very tiny left pleural effusion"
Yep, googled it and I am terrified.

Here is the thing, a week later is when I had the CT scan done. That report says "There is no pleural or pericardial effusion detected"

What the heck???? What am I supposed to do????