Factor v Leiden?!?!

My family Dr. Said that having this may have been why I have miscarried twice and have not been able to conceive (also my sister 3 miscarriages and factor 5 is in the family). But my gyno said that wouldn't be why and that 2 miscarriages isn't anything and to try again and don't do anything different.  But I feel like with my sister and I's track record I'm just going to miscarry again.  It's so emotionally painful that I don't take trying again lightly.  Any suggestions or helpful knowledge?