Preterm labor

So, I'm 29+6 with baby #3, and he is following his sisters' early deliveries, my first arriving a week before her due date, and my second arriving at 36weeks. With my first, I began dilating at 36 weeks. It progressed with no "real" contractions until I was nearly at 10 cm. The only reason i made it to the hospital was because i mistook bladder incontinence for my water breaking. 12 visiting family members got stuck in the delivery room because I had been told I had hours and I was ready to push at their first cervical check. I was still sitting up and holding conversations at that time. Now, with my second, I began dilating at 32 weeks, and having what I was told were false contractions on and off, daily. I was sent home for not being in "active labor" four different times in the next four weeks, at 2 cm, 3cm, and 4cm dilated and increasingly more effaced. I wasn't offered anything to slow or stop the progression of labor and was treated as though her early arrival was my fault. My concerns were not taken seriously, and because I labored differently than most women, I was brushed off continuously.My contractions never became regular. My water never broke. I did not discover my mucus plug. I arrived at the hospital the fifth time, to discover that I was a whopping 7cm dilated. She arrived two hours later. I was talking, walking, and even laughing up until my water was broken at 9 cm and she arrived 20 minutes later.

Ever since discovering I was pregnant a third time, I have been cautioning my health care providers as to my strange labor history. I have been insisting that he will arrive early. I have asked and been denied medical help to prevent preterm labor on two occasions, and asked and was denied help stopping what I truly believe to be preterm labor last night. I'm having my "fake" contractions. And I'm feeling pelvic pressure. And I checked my own cervix after being sent home with a pat on the head and discovered that I was at least 50% effaced and easily 1cm dilated. And I'm Terrified that they will keep brushing me off and ignoring me until he arrives dangerously early, and possibly without the immediate medical attention he will need. Any advice?