30 weeks and 1cm dilated is this normal?

It depends on what your previous childbearing history is. If this is the first time in your life that you've been pregnant, it's unusual...But if this is your 4th child, or if your've had miscarriages or abortions, depending on what the procedure and how far along you were, it might not be unusual. Your health care provider is the best one to tell you how significant this is, based on what number pregnancy this is for you, whether you've carried previous babies if any to term, how big the baby is -- or babies are (twins often don't carry all the way up to term), whether your amniotic sac & fluid are intact or if you are leaking amniotic fluid, whether you are having contractions or not.