I am and I do. Outbreaks are not too difficult to treat during pregnancy. You can still have steroids, which is what they would do even if you weren't pregnant. I had one relapse during the first trimester when I was pregnant with DS, but it wasn't too serious so I decided not to do the steroids. It went away as soon as I hit the second trimester.
So far this pregnancy, there have not been any relapses. Were you diagnosed before getting pregnant or is he just now diagnosing you with MS? If this is new, stay calm. MS is different for everyone, but a positive mindset goes a long way. I've had it for 8 years now and I still do half marathons and triathlons, even while pregnant with my second child. My brother is worst case scenario with MS, but he was never on disease modifying medication (he was diagnosed 20 years ago).
Please feel free to PM me if you have questions and again... stay calm and enjoy your pregnancy...it will be ok.