Congratulations, ! What wonderful news! I may not be in your exact situation, but I have four kids and my youngest was born when my oldest was 10. My biggest space between kids was 4.5 years. I hope your whole family is excited about this surprise (though it's okay if some family members are adjusting to the news). We have had many community members that have had kids while living with MS. In fact, one of our contributors had triplets after her diagnosis. You can read more about her experience of going from one to four kids here -- https://multiplesclerosis.net/living-with-ms/pregnant-triplets and here -- https://multiplesclerosis.net/living-with-ms/triplet-pregnancy. She shared a fair amount her pregnancy journey here, and also shared about adjusting to a suddenly large family, so if you look her up by name, you can read her whole catalogue of articles (Calie Wyatt is her name).
Just like going from one to two kids, adding a third to the mix will definitely be an adjustment, but you've done this before and you can do it again! And, the good news is that you aren't going to be dealing with toddlers AND a baby at the same time (those early years with littles are EXHAUSTING, aren't they?).
Again, congratulations and I hope you get some great feedback from other community members with multiple kids. I hope your pregnancy is smooth and uneventful!
Best, Erin, Team Member.