Period changes after vaccine - how long?

[Donatella]

DD1 (13) had her covid jab (Pfizer) 2 weeks ago. Her period was due a few days later but is now 9 days late. She is thrilled as she hates having her period, I'm just curious as to how long this may last. Any experiences to share?

I had my first pfizer in February and my period was a couple of weeks late.. it was also very heavy the first time after. They are currently now every 3 months rather than monthly! But they last twice as long!

Hmmm shed love the 3 monthly cycle (beats her current 3 week cycle 😭) , not sure she'd cope with them being any heavier though (or more to the point I'm not sure I'd cope with the drama!)