I attended the preconception clinic in Huddersfield - just mentioning as sometimes different things happen in different parts of the country.
With me, as my HBa1c was fine, I was essentially given the green light to go ahead and prescribed a higher dose (5mg) of folic acid to start taking immediately up until 12 weeks pregnant. If though your HBa1c is less than perfect, be ready for the scare stories about what may happen if you conceive before they're tightly controlled. I was also given the range of blood sugars they expected me to keep during pregnancy - very tight! - and advised to start getting into the habit of keeping them like that.
I was booked in for a repeat HBa1c test 3 months later but also given my consultant's secretary's phone number and was told to get in contact directly if I conceived before the 3 months was up - which I did! I phoned and was seen in the maternity clinic two weeks later where I was introduced to the obstraetician, the dietician and the midwife.
I was also booked in for an early dating scan at 7-8 weeks. I am currently pregnant with my second baby: with my first I was then seen every month in the clinic through trimester 1 and 2 and then once a fortnight in trimester 3 though was told that if my blood sugar control wasn't tight then it would be weekly visits.
Good luck! x