Yes, I suppose it could happen again. But it also could NOT happen again.
What does your doctor have to say about it? Have you shared your fears with him or her?
It is okay to be scared. But please try to keep your fears from overwhelming you and try instead to hold positive thoughts for yourself and your baby.
If you are religious, you might pray for inner peace and ask that your baby grow strong and healthy so that he or she will be born to you and your husband in God's perfect timing.
If you are not religious, that's okay too (I'm Agnostic, myself).
Just try to keep your thoughts focused on the positives and cancel out your thoughts of the negatives, then follow your doctor's instructions and wait for time to pass.
All the best to you and your soon-to-be family.