I've had 4 miscarriages in a row, should I give up?

I am 20 years old, my and my Fiance have been trying for the past year to have a baby. I have never had a successful pregnancy although my mother has four, and my sister has three healthy, beautiful children. I have tried taking an 81 mg baby aspirin everyday. I have tried taking hormone pills twice daily prescribed by my doctor. I have even tried quitting my job and staying off my feet, even not having sex. All to no avail. My first pregnancy was the longest, the baby stopped growing shortly after hearing the heartbeat for the first time. All other pregnancies ended almost before they began. I am currently on medicaid which prevents me from being able to see a specialty doctor. So if anyone has any advice, I would greatly appreciate the insight.