Due date wrong

Ever since my first ultrasound back at 7 weeks... my due dates been wrong. Im high risk and have multiple health issues sadly. So ive had multiple ultrasounds. Each time my baby is measuring 3 weeks bigger, starting at 9 week ultrasound! Well according to my doc yesterday i was 34 weeks, he sent me to a different ultrasound tech and she said my due date should b October 10th not October 30th, baby is 7 pounds measuring 37 weeks. I will not go into labor on my own til its too late. This is 4th pregnancy, hopefully 3rd live. Doctor will not induce me before oct 23rd, that puts me at 39 weeks but baby at 42 weeks and with him being 7 pounds right now, what will he weigh in 5 more wks?! Im very scared for my child's health and for mine. This is the 2nd o.b. ive switched to. I feel as if i need to try to bring labor on myself but have no idea where to start, ( i don't need negative comments) as ive stated before 4th pregnacy and not once have i been able to go into labor by myself. Ive never had this problem where they were off so drastically on my due date either, and this is 2nd pregnacy with my health problems. Definetly my last pregnacy. For those who will not judge, have any of you been through this? Im very worried.