When it comes to calendars, were there any additional months that were once apart of the 12-month cycle we use now? ?

Per the source article, at one time the calendar had only 10 months. You may do further historical research on calendars to see if any civilizations used one that had more than 12 months (although the 12 month calendar is based on 12 lunar cycles in a year). 

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i dont think so

Well...

if they were part of the 12-month cycle

then

how could there be additional months?

But the answer is: no

the Julian Calendar was strictly a twelve-month calendar

and its successor, the Gregorian Calendar

is also strictly a twelve-month calendar.

I believe so. In some cultures. I can not name them. But there are 13 horoscopes.