How long did u stay 4cms?

Had my apt today. Got checked for the first time at 37 weeks. I was 4cms and 70% effaced. She said baby was so low and would have been here already if his head wasn't tucked behind my cervix. Not sure what this means. She hooked me up and I was having contractions so she sent me to the hospital for further monitoring. She said being my second baby she didn't want to send me home if I was progressing and contracting so we are waiting to see if I'm still contracting and progressing here at the hospital. Think they will send me home or keep me being 4cms? Contractions arent as painful as you'd think. Just uncomfortable and not regular.