Was wondering if I could file a lawsuit against hospital for failing to do sonogram after complaints of vaginal bleeding?

6 weeks ago while at work after using the bathroom i noticed spotting and immediately called my doctor who told me to go to the E.R.. I was going on 21 weeks and was sent to labor and delivery. The nurse listened for a heartbeat and everything seemed to be fine according to them and a midwife later came in to do a pelvic exam and she assured me as well that all was well and i was discharged and sent home to rest. The following evening my water broke and the next day i vaginally delivered my son who died right after birth. The complication was due to an incompetent cervix and i feel this could of been prevented if i was properly looked at and given a sono to detect the slight dialating of my cervix i also feel as if i should have been checked by a doctor instead of midwife.