Recurrent miscarriage

I've had an array of results done after three miscarriages (2 natural and one missed miscarriage which requires a d and c) and they pretty much came back clear. I've had extensive tests done for clotting, NK cells, progesterone, husbands sleek etc
Although in my third pregnancy they found out that I have polystic ovaries which the dr said is common and fine because I've fallen pregnant three times in one year. 
The gyno at the hospital thinks I'm suffering from a case of 'bad luck' and encouraged me to keep trying. 
Does anyone have any advice or any hope/positive stories?
Thank you girls. God bless xxx