Hi congratulations on your news. I too had an unplanned pregnancy, and can offer the following advice
1. Get a referral to a diabetic midwife asap. Best way to do this is to speak to your GP, or you could contact the antenatal unit yourself as well, and they can advise on the referral. They should see you within days, not weeks. Both my pregnancies I was seen pretty fast.
2. Begin to test your blood sugar before and after every meal, on waking, and before bed. The targets are strict but don't worry if you don't meet them 100%.
3. Most hospitals run dual clinics where you will be seen by a diabetes midwife and a diabetes consultant in the same clinic. They will usually see you every fortnight during the pregnancy if you are coping ok, or possibly every week if you are struggling or towards the end.
Best of luck with it, it can be a difficult time to manage your diabetes. Tommy's have produced a guide for pregnant diabetics (which I contributed to) so look that up if you want to find out more.