worried

so im 17 weeks and last week the dr in the er where the on call ob done a quick scan due to pains i was having and told me my cervix is only 2-2.5cm long. but isnt concerned even tho i have a partial prolapsed uterus. is it just me veing paranoid or should they be more concerned because also in my last pregnancy i had preterm labour at 29weeks. i feel like there not as worried as they should be and im worried about an incompent cervix.