Advice please!

I would wait until after. Most of a pill is made up of substances which are not the active ingredient - it may contain substances that contribute to blood sugar, albeit in a small way. The Metformin should be taken with food anyway.

If it was me and I wasn't told specifically not to take my meds I would continue as normal, but seeing as its 10 am its probably not that far a delay from the normal time you would take it............

then you can just ask at clinic.........

I don't think I have ever had a fasting test but I don't think the reading they receive from you will be used in any pin point accurate calculation, so all will be well....