Sweetsister - it will almost definitely move. (As long as it was not actually crossing the cervix.) After 20 weeks, the lower segment (area closest to cervix) is what expands as babe grows. As it expands it lifts upward taking the placenta with it. I have very rarely seen anyone who still had a low lying placenta at 30 weeks.
Oh, and I have lots of contractions daily. I actually think it is slightly less than with my boys but here every day many times per day.