Side effects of the levo are, typically, symptoms of hyperthyroidism
; however, shortness of breath, with exertion, along with heart palps, nervousness and
flushing can also be symptoms of too little medication. I had them all when I was very hypo. They went away when my levels became adequate.
If you're due to see your doctor in a couple weeks, you should also be due for new blood work; that will tell you whether your levels are getting too high, but I'd doubt that they are.