30 weeks and "short" cervix

Hey! So I went for my 30 week appointment. They measured the baby, my cervix, and the amount of amniotic fluid. Baby is growing well and healthy. 😊 However, they mentioned my cervix is short. According to my doctor normal is 2.5cm to 3.5cm. I measured 1.5cm. The doctor told me I need to be on bed rest for the rest of my pregnancy and gave me a prescription for progesterone suppositories.