Statistics show us that many women have a miscarriage, and that the incidence is 15-20% of clinically diagnosed pregnancies. As you have already had a successful pregnancy that indicates your reproductive system is capable of carrying a baby to term. It is only if a woman has recurrent miscarriage (3 or more in succession) that additional tests are done.
I can appreciate how distressing it is for your pregnancy not to continue but do be assured that there was nothing you could have done to change things.
Going forward then we usually recommend that you do not try again until you have had a normal period, as your cycle and hormones may be slightly off for a few weeks after this loss. You should continue to look after your health with plenty of fruit and vegetables, do not smoke and consider a prenatal vitamin with folic acid.