I Recently About A Month Ago Ran Out Of Thyroid

I recently about a month ago ran out of Thyroid medicine. I accidently thought I was using the correct medicine and it turned out to be Vesicare. Now I am trying to get another prescription from my doctor for the Thyroid meds I need but haven't heard back from his office yet. Will this be a problem? I have noticed I tire out earlier in the day than I used too.
Thank you,