Insurance. Help?!

I don't have any insurance, I live with my parents a few days a week and the rest with my fiancé or grandmother. I'm getting married September 19.. And neither of our jobs offer insurance. I'm currently 15 weeks... So here is my question, who or where is the best place to go to get maternity insurance?! 
We don't make a ton but We do have about 600$ left over after all our payments are paid.   I'm 20.