What could it be? I was in the ER last night for chest tightening, pain, and shortness of breath. They did a cat scan and ruled out PE, blot clot on my lungs, and prescribed me an inhaler t i use for when if I get the tightening in my chest anymore. But today I'm woke up and my chest hurts about 3x as much as it did yesterday and it seems like whenever I get the pain to subside, it just comes right back. The pain is mostly on the right side of my chest. Also, I'm 34 weeks pregnant and I'm concerned, but I don't want another ER visit.