Okay, so it's good news all round today.
As a recap, I've never had an OB before, or visited a hospital for prenatal appointments. So this was all uncharted territory! lol
First off, our new OB was punctual for our appointment (wow!). And she gave us plenty of time and information. We liked her. She's youngish, and has fraternal twins herself, so knows what I'm going through.
She said I'm doing fine, but did write me a prescription for extra folic acid and iron. My blood pressure is also a little elevated (a bit early for that, but oh well), so she suggested I take extra calcium and baby aspirin to combat that.
She did *not* ask why we went for IVF, so I was relieved to not have to "go there". lol
She did mention that embryos who have undergone ICSI have a slightly
higher chance of birth defects (~4% vs the usual 1-2%). So that was a
bit of news.
Then we did the u/s. It showed that the twins are looking healthy and on track. She offered to do gender assessment and I eagerly accepted!
Twin B is a "definite girl". She had trouble imaging Twin A's bits, but said it is "most likely girl". Yay!!! Even though we already "knew" the gender (PGD), DH and I felt excited and surprised when she told us, almost as if we didn't. LOL!!!
Oh, I almost forgot... when we were getting ready to leave, I unexpectedly saw one of the excellent sonographers from the local clinic! It was F, who did my emergency ultrasound during her lunch break the day of my initial SCH bleeding, when I was so panicked that I had miscarried. Turns out, she works mostly at the OB's hospital, but also works 1 day per week at the local clinic. It was such a lovely unexpected surprise! She completely remembered me, so we hugged, and she asked how the twins were doing.
BTW, at my last u/s (nuchal at the local clinic), the sonographer had said the SCH was resolved (or nearly so), but today we did see it still there, albeit quite small. The OB was not concerned, and said it is expected to resolve completely as the pregnancy progresses. She did not seem concerned in the least. I have not had any bleeding or spotting in 5 weeks or so, and am completely back in my normal routine, so I am not worried either. (I did ask if a past or current SCH puts me more at risk of premature labor, etc, and she said possibly, but again, she did not seem concerned.)
So overall, a good experience. She said if I make it to 34-36+ weeks, that will be excellent. She said I can keep working for as long as I feel good and the twins are doing well. And that is my goal. I think I can do it!
So I have already been telling people today we now know it's two girls. Everyone is so happy for us. That has been an amazing feeling. Yay!! 
PS - Weight gain so far is TWENTY POUNDS!! Argg!!! lol