Pupillary Distance

Went to the eye doctor for updated prescription and I asked for my PD, they said it was 52 and I got a pair through them with my insurance and didn’t have to pay anything

However when ordering online most of the adult glasses I come across don’t go below 54 PD. I remeasured at home and I’m getting a 62 PD?! How am I getting a 10 mm difference from optometrist and myself?