Do your ovulation dates tend to change monthly?

Bear
I was under the impression it tended to be fairly consistent, especially for me bc I pretty much always have a 28-29 day cycle. Last month I think I ovulated like day 8 or 9 into my cycle, but the months before it was always on the 14th day. Does anyone else have the dates change on you even if you have a consistent cycle?? Thanks girls!