Seeing as it doesn't really matter if you're a few psi over or under, I wouldn't let it worry you unduly.
Just stick an extra stroke or two on the pump once you get to the required pressure if you must.
Sometimes I have to give the pump head a good wiggle to get it off, and what sounds like a lot of air hisses out. Tyres still feel nice and solid afterwards though, so not that bothered.