Empty sac.

I missed my period for this month I’m not exactly sure of the day my last period was it always comes in the beginning of the month though within the first week so I know it was during the first week of March. I went to the doctor yesterday and there was only an empty sac and the doctor said I had a bleed in my uterus. They did blood work to check my hcg levels I go back tomorrow for more work. I haven’t had any bleeding just minor cramping which I had with my first child. Has anyone had this before and it turned out to be okay?