17 and pregnant!

I am 17 years old (18 in two months), and am trying to have a child. My fiance is 21. We both have jobs. I currently work as a Certified Nursing Assistant and he is working for a Company that helps the Mentally disabled. About a month ago I found out I have ovarian cysts. The doctors told me that if I have the desire to have a family the smartest thing to do was start soon, due to my cysts. Im scared considering im so young. Im extremely terrified that I cannot conceive Please any advice or stories would be helpful!!