Yes, I have fibroids. There is the possiblity for them to grow in the pregnancy. Mine have gotten quite large and now cause me quite a bit of pain. I was actually hospitalized for pain around the 25th week (I am now 32 weeks). They can cause problems with delivery if they are in the way of the baby being delivered vaginally. They won't know this until they see how the fibroids develop during pregnancy. One of mine is the size of a grapefruit in there with the baby...and the baby kicks it all the time. It is not fun.
If your fibroids are small, I don't thik you have anything to worry about. The doctors will continue to monitor them throughout the pregnancy. Many women go through their whole pregnancy with no problems from fibroids, I just happen to be one of the unlucky ones.