Miscarriage

I had two positive pregnancy tests last week, they were faint but positive. I started bleeding heavily this morning so I went to my OB, and he did another test and it was also faint. I haven't fully miscarriaged (yet), but he said it would more than likely happen. I go back in a week to get checked again. I'm wondering if anyone has had this happen and end up not miscarrying and have a full happy pregnancy.