Totally normal and quite common.

Optometrists are very reluctant to prescribe lenses for pregnant women for this reason - the change is usually temporary and you would almost definitely need a different prescription (if any) once the baby is born. So unless you really are incapacitated it would be a huge waste of money.

I had my eyes lasered a few years ago and when I got pregnant for the first time I actually had to dig out my old glasses in order to see properly while I was driving. Once DS was born my vision went back to normal.

Interestingly this never happened when I was pregnant with DD or this time around either. Only with DS.