What Causes A Mucous Type Of Vaginal Discharge?

I've been taking Levothyroxine0.05 for a little over a month. When I started, my menstral cicle was more frequent (3x in one month) I have told my OBGYN about it. But, my main concern is that I am also experiencing a vaginal discharge and is not likea yeast invection type of discharge. It is more of a mucosus/muscular type of discharge; what could this be and could it be a side effect of the medication? It's the only med. i am taking.