Threatened miscarriage

Early yesterday morning I awoke to use the bathroom and felt a gush of fluid and immediately went to the bathroom. My underwear was soaked in blood and some kind of fluid, so we go to my doctor immediately. She checks my cervix and it's closed, everything down below looks good. Found a heartbeat on the mini machine but still sent me for an ultrasound.

We saw our little squirmie worm on screen still kicking and dancing and we're so relieved. I've been told I have a threatened miscarriage and she wants to see me back at the office Tuesday. Has anyone else had a threatened miscarriage and still carried their baby to full term. I'm 13 weeks and 4 days with my first pregnancy and I'm completely terrified.