Hi. I Am Almost At The End Of My Pregnancy

Hi. I am almost at the end of my pregnancy but I believe my due date is wrong. My period is usually 7 days long and pretty heavy. My last sort of normal period was January 6-10 and it was late and light. Then on February 6-8 I barely spotted enough to count. On February 18th I had some light pink once that day. My doctor put my due date on November 22nd., but my body is already contracting and having other prelabor/labor signs. How can I make my doctor do an ultrasound to check to see how my child is doing? I'm already leaking clear fluid every little while, contractions have been 20 minutes apart for almost a week, and I can tell my body is getting ready. What can I do?