Funneling of cervix??

Shelbi
A week ago I had an ultrasound and my doctor told me that apparently the sac that the baby is in is funneling towards my cervix. So she took me off work and said no lifting heavy things and said I'm on pelvic rest. She said that since I'm just shy of 20 weeks that this is really bad because I could potentially start dilating soon. I've noticed the last 3 days I've had a lot of blood tinged mucous and discharge and have been having horrible cramps. Then when I went to the bathroom today it felt like something was falling out of me. I went to women's special care and they did a urine test and checked to see if my cervix was open and it wasn't, but it was really soft. They said there is nothing they can do if I go into labor and sent me home, putting me in bed rest for the night and said to come back in the morning to do an ultrasound with my OB doctor. Has anyone else had a problem like this? I'm list as to what to expect and know it's serious but I just don't think it's hit me as to how serious.