35weeks & dilated 3cm! Help!

Hi ladies! I went to the hospital yesterday with really bad upper abdominal pain and when examined they determined I was 3cm dilated. Since I didn't dilate any further when I was at the hospital they send me home with bed rest instructions. Has anybody dialated 3cm early in your pregnancy and if so what happened? Did baby come early or did he wait till due date. Please help I just need advice FTM and freaking out!