What are the chances.....

I lost my soon 20 weeks into my pregnancy on May 22, 2009. I've had irregular periods, been on and off birth control to try and regulate and get my hormones on track. I've been wanting to try and conceive again but 1. I'm afraid I won't ever be able to conceive considering I've had five years of unprotected sex and 2. I don't know what the chances of having another "miscarriage" (I'm not sure if it's still called that when you're that far into the pregnancy) are since i still don't know the cause of the first one. I'm going to get the results from the hospital from the "miscarriage" tomorrow so hopefully that will give me some type of answer. Does anyone know what any type of chances are for either of the two statements I made are?