Late periods!?

I’ve never had a late period so just wondering for those who have had a late one:

My cycle is normally 28-29 days but I was 9 days late therefore glow is now predicting my ovulation to be 4 days later(CD18 instead of usual CD15) and my cycle to be 31days instead of 28-29. Did your period go back to normal right away? Or did it take a couple cycles? And did you ovulate later (with opks) ? ( I’m praying I do ovulate later seeing as s/o is out of town)

Thanks so much!