a level results uncertainty

I fear my grade changing. Hi so I got my a level results of A* A B yesterday. The grades are close to what i was expecting so i was really happy but after going home and watching all the videos of other people getting messed around and with this whole year being a mess I have a lot of anxiety that my grades may change even after results day or my eyes were playing a trick when I opened the email. I forwarded my results email to my mum to read cause I genuinely thought I was reading them wrong. the anxiety is building up and is even higher after I phoned AQA today asking if I could just hear a confirmation of my results on the phone. they said they couldnt do this and my results should stay the same. but he also called them provisional till i got my certificates. a level grades dont change after results day right? and how likely is it that my college may have made a typo when giving my results.