My son is nearly 15 now, so it's been a while, but I started on folic acid a month or so before we started trying. It’s a great start for your baby if you get yourself in the best health possible before you get pregnant, it is a scary, exciting and lovely time! But keeping your glucose levels in range and stable is key, but I’m sure you know all that. It’s doable, and the added incentive of the baby really gives you the motivation to do it - if you can get a Libre CGM, it’ll make things an awful lot easier, as insulin requirements change a lot during pregnancy. You’ll be very closely monitored the entire time, possibly extra scans so that they can monitor the baby’s size, so that they can bring it on a little early if baby is getting too big. I had my son two weeks early, not because he was big (he was 7lb4oz) but because I had such bad sickness throughout. My consultant said it was time off for good behaviour

I had an HbA1c of 5.6% at the time, probably my best ever. Your baby may get some extra monitoring after birth, my Ozzy was in the special care unit for a couple of days because he was a real puker and slightly jaundiced.
But as an expectant mother with T1, you’ll get the very best care.
I also measured my temperature every morning as soon as I woke, because it’s a very good indicator of when you are pregnant. I started to do this to work out when I was laying an egg, and therefore the best times to do the do. When you ovulate, it goes up a little, and stays elevated until the day your period starts. If it’s still high the day that you’re due, it’s highly likely that you’re pregnant - I wanted to know at the very earliest opportunity so that I could make sure my BG was kept under very tight control. The number of days from ovulation to your period is the same every single month, although the time between the first day of your period and when you ovulate can vary. Not sure if that’s helpful or not!
Wishing you all the luck on this very exciting phase of your life xxx