Levothyroxine causes acne?

My endo said my blood levels were fine but she found two nodules so told me to take half a pill of 25 mcg to shrink them. She said because it was such a low dose it wouldn't cause any side effects but about 2 months after I started taking it, I started getting acne. I have NEVER suffered from acne before, not even in my teenage years (I'm now 29). Could it be the meds or something else? I really haven't changed anything else? Please advise.