Hello, @LovetoHike, and congratulations!
I have been hoping to connect with other T1D women who are currently expecting and so will reply, even though I don't have PCOS. I just started my 14th week and also had an increase in basal needs as soon as implantation happened (I actually knew when since we used IVF that cycle), to about 20-25% over my prior levels. This is common due to the immediate increase in progesterone production (still released by the corpus luteum) which has a countering effect to insulin.
The lows you were told to expect are still likely to come, but only once the placenta develops and takes over hormonal production and delivery to the fetus. (A bit more on this from a related recent discussion here: http://www.tudiabetes.org/forum/t/10w-insulin-sensitivity/60909). So make sure to keep an eye out for that transition after your 10th week or so. If you don't wear a CGM, I'd recommend waking yourself up to test around 3am, although lower fasting levels might be a sufficient sign.
I personally see a high-risk specialist and knew that would my choice from the time we were ready to start trying to conceive. Originally, my endocrinologist informed me that his professional insurance does not allow him to see pregnant patients which I found shocking and disappointing. But then I made a pre-conception consultation appointment with the local maternal-and-fetal medicine center and the doctor we met there was great! So I decided that he would be sufficient and I won't be seeing my regular OB/GYN either during the pregnancy and delivery. I think the options are different depending on where you live / what is available, but I actually would highly recommend a MFM specialist. You get to have a lot more frequent checkups (including ultrasounds!) and to me that's only an advantage.
Normally (i.e., eating what I actually feel like eating), I consume 75-100g carb/day and focus on variety and clean, whole foods more than on the carbs themselves. Since I have great results this way, am not interested in anything lower than that since it will mean a major shift in lifestyle, but if I was struggling with BG results, I might feel differently. Related to this, from my perspective, Bernstein and his followers are a little too fanatical. So the general approach (lower carb amounts than what the "typical" American diet contains) is actually great, but the details of the recommendations (under 30g) are simply not for me. Now, during pregnancy, I will feel OK ramping up the carbs some, as my natural sense of hunger might suggest. It hasn't happened yet, but I anticipate my appetite will change, esp. in the second half of the term. Also, I haven't yet had to change my I:C ratio, though I expect that is coming later too.
As I said, I don't have PCOS, so I will leave the last question to others to chime in on.
Best of luck!