maternity leave ? different due dates !

I think I decided to leave my job June 9th and I'll be 38 weeks and 2 days then, my first doctor said my due date was June 13th and it stayed that way for the longest, I was just going to have a small baby, well the doctor I go to now said she doesn't know where I get june 13th from and it's actually June 20th and the other doctor was wrong and so far that doctor (doctor #2) only did one ultrasound while my first did one every 2 weeks I went. Which one should I go with?