There is the same chance that it could happen again as there is that it couldn't happen again. Try not to worry too much. Just take it easy and do everything you should be doing to take care of yourself and your pregnancy. Take your vitamins etc.
i dont thnk that only because it happened last year,itll happened again,but it depends on hows ur prgnancy doing.If ur doctor says positive things u should worried only if u see something unsual,go to the doctor...gl:)