Just Had Pupillary Distance Measure And Different From Before?

I just had my pupillary distance measured today and it was 33 by 32, however just a week earlier I had it measured and it was 34 by 33… the optician said all my previous measurements for as long as I was wearing glasses was always 34 by 33…
How come it came out to 33 by 32 today (she checked it like 5 times)… I have been pretty stressed lately which I heard could dialate your pupils… would that affect the reading?
its 2mm off from what it always was, i’m thinking of going back tomm morning to recheck. My perscription is -2.25 on both eyes (no astigmatism), will 2mm make a difference?
thanks