I would recommend having a chat with your GP or DSN about this. When we were toying with the idea of a second baby, my GP referred me to the diabetic consultant in the gynae dept at the local hospital. It was enormously useful, she gave me all the possible scenarios, medications, complications, preparations, and support, and there are many, many things to consider! It is never going to be as easy or straightforward pregnancy for an older diabetic than a non-diabetic. The only thing I would say in addition to getting some professional advice is that you need to be in as best "shape" as possible to do this, ie- as low and controlled BS as you can reasonably manage and maintain I would think. That's the message I got loud and clear!
Good luck