Have you been pregnant before? If so, that experience should inform your current decision. If you went into remission during pregnancy, or stayed in remission, you are likely to have the same experience IMO.
If you have not been pregnant before, the odds are about
30% that preganncy will cause a flare. I'm not certain what the duration of your current remission has to do with that risk - I would push on your DR to answer that question.
If your iron stores are low, she may be anxious about
getting your nutritional status up to a higher level before you begin a pregnancy. Personally, I agree with you and would not wait. It is likely that you will not conceive immediately anyway, so what's the harm in starting to try?
Oh, and I suggest you start your pregnancy with a regular OB. You can always move up to a high risk if your status changes during pregnancy. Of course, if you've had surgeries or know of strictures/scarring/fistulas, that would probably change the decision.
I started experiencing symptoms of IBD after the birth of my 1st daughter. I got pregnant with my 2nd daughter 18 months later; I was not in remission, but pregnancy did improve my bowel function. My illness flared after my 2nd daughter was born.