Threatened Miscarriages

Hello I’m new here and I have to ask has anyone ever heard or experienced a threatened miscarriage. I went to the hospital and was informed that I had this. But not more information on the matter. I didn’t get to see a sack or hear a heartbeat. Only advice was to see my doctor in 48 hours. Has anyone had this happened and pregnancy and baby were fine. I did research and see that people have continued on and had healthy babies. I’m currently under 20 weeks and this seem to be a common thing.