1 cm dilated at 32 weeks

Woke up this morning to terrible cramps above my belly button, like right over my ribs and reaching around to the middle of my back. I thought it might have just been heartburn or a stomach ache but it was unbearable so I called my doctor and he said to go to the hospital, and it turned out to be contractions! I was one cm dilated but they sent me home because I didn’t progress any within four hours. Was anyone else dilated this early or having bad contractions??! Always had a feeling baby boy would come early as he is measuring three weeks ahead but I’m nervous!