How often to test? Establish how many test strips your GP is willing to dispense and demand twice that
Seriously, my test strips come in boxes of fifty which isn't quite enough for twice a day testing, and, so far, they've fulfilled my "inbetween big prescription top-up requests" without problems. I test first thing every morning and then later in the day. Later again if I feel that the wasn't sufficient change between the first two tests. (I'm on max dose gliclazide, by the way)
It's important to remember that each blood glucose test is a snapshot of what your blood was like at the moment your blood made contact with the testing strip. Testing once a week, as your nurse suggests is the equivalent of having a school photo done every year, when what you need is a home movie!
My testing spreadsheet notes conditions before the test: a Thursday morning test might say "meal with S&L last night" (liable to wine and calorie laden), while a Thursday afternoon test might simply note "after dogwalk" (brisk walk in the hills). It's only by noting what you were doing/eating before the test that you can make sense of the results.
My view is that frequent testing allows you to build up a picture of what suits you and what works for you in keeping your BG within the magical 4 - 7 mark. It also allows you to build up a picture of how you feel when your blood sugar goes outside those boundaries. I'm sure my recent adventure in Snowdonia (I think it's under "Things NOT to do" in General Chat) might hve turned out differently had I not been aware I was going hypo and that keeping the driver of the car calm, focussed and on the fastest road back to our village was our (and my!) best bet. By the time we got home my BG was under 2.0, but it would have been a lot worse had I allowed the driver to dither...
So test, test, and test some more: it's all about learning to hear what your body's telling you.
One question to those diagnosed more than two years: when does irritability as a symptom of uncontrolled diabetes disappear? There's an entire village in Wales dying to know... ;-)
Steve