I don’t know what’s happening

So since my mc in feb and i think before, I’ve ovulated later like cd18-21. This month, the month before I’m supposed to get married i get my positive opk at cd14. I mean we are bding like crazy but I’m just wondering why for a year i would ovulate late then out of no where ovulate within “normal” time? Not complaining at all just curious. At least this way AF will either be done and completely over with before i put on that huge fluffy dress or we will get the best wedding present ever. i know cycles change but for it to be consistent for so long then out off no where for it to change??