Just got in from the hospital. I woke up this morning and tinkled and saw light brownish blood. I went to the hospital…

Just got in from the hospital. I woke up this morning and tinkled and saw light brownish blood. I went to the hospital and they said its a threatened miscarriage. They did blood work a pelvic exam and an ultrasound. The ultrasound tech said the baby is fine and the heartbeat is strong. My cervix is open. Blood test came back fine. Should I be worried? Has anyone experienced this?