Jellybean is right, you can get a machine cheap but unless you have a card from the national diabetes scheme you pay a lot for the strips, something like $100 without the card and $15 with it.

I have GD in this pregnancy and had it last time too, I had the sugar test at 9 weeks this time because I was high risk and was on insulin by 17 weeks, last pregnancy I had the gtt at 18 weeks which I passed but by 24 weeks was feeling awful & knew I had it, the 2nd test confirmed.

Limits are changing at the moment but generally it's meant to be under 5.5 fasting (some hospitals want it under 5) and mine does 1 hour after eating not 2 hours and they want it under 8 at one hour, so if you start eating at 12 you check it at 1 even if it took you 30 mins to eat, I don't necessarily agree with that but that's the current theory at my hospital