What Causes Irregular Periods After A Miscarriage?

Last 28/06/2010 some resion i do missabortation after that my period c't come reguler... now i am not pregnent but i am not get my period from 2 months what to do....before misabotation my weight is 60 kg and now 69kg.. my dr. say everything is ok. i want to pregnent but my period is delay every month.. Plz guide me what to do....Plz