Preterm birth

I saw my dr two days ago and asked for an exam because the baby had definitely dropped and I have sharp pains, contractions and pressure. He said I'm definitely gearing up for labor I'm dilated to a 3, bulging membrane and he can feel the head. I'm 32.4 acroding to the very first fetal ultrasound measurements and I'm 34.2 according to my last period. My first son was measured the same and came on my due date that was by my last period. So I'm not sure where I really stand he hasnt measured the baby since that first dating ultrasound. I had to have steroid shots to develope the babys lungs in prep for preterm birth. He went over procedures and now I'm just stressed to the max. I dont want to be flown to pheonix in labor. Theres no Nicu in my city. Anyways now that your updated my main question was has anyone who went through preterm birth noticed any extra signs you could inform me of. I'm definitely not constipated and my boobs are all of a sudden filling with milk. They are leaking a ton and getting heavy which didnt happen until after i had my first son.. I'm just so stressed idk what to do with my mind RN.