I myself only test before meals. That helps me to make an informed decision on what to eat, as I’ve learned how different foods effect my blood sugar.

Additionally I have a problem few other have, in that my internal blood flow is reversed, so it takes longer for my blood sugar to settle. I also test in an alternate site (my legs), so that testing before meals has worked out best for me.

What really matters is your A1c which tells the bigger picture, so your testing should help you on a day-to-day basis toward that goal. But remember that if you stagger when taking readings (before, or after 2 hours, etc) make sure to document when and any unusual circumstances, etc. so your readings will make sense several days later as well.