Blighted Ovum, in which the loss of the pregnancy occurs even before the implantation of the fertilized egg in the endometrium lining can take place, are a very common occurrence and many a times produce no symptoms at all.
This takes place in the first trimester of a Blighted Ovum cycle, way before she is even aware that she is pregnant in some cases.
A blighted ovum is really a bodily occurrence than a fault that is brought on from the outside. You can still try ways on avoiding this situation, by taking care of your health during that time of planning a conception. I wish you luck.
However, miscarriage need not necessarily spell a doom for your future chances of pregnancy.