Brown discharge :/

Hi ladies.. On Thursday morning I woke up and had this gooey snot like discharge that was a dark gray color and also brown on the toilet paper when I wiped. I got so scared I went to the hospital and they did blood and urine tests..which came back fine and did an ultrasound which showed no bleeding or fluid anywhere..and saw the baby and the heartbeat. They told me it was normal and was probably from the baby embedding itself more into the uterus. The ultrasound put me at 6 weeks 3 days. Friday I had more light brown discharge.. About 3 times throughout the day and also had that snot like discharge again.. Only it was an off white color. I haven't had any cramping..but I can't stop freaking out. I'm afraid to do anything. I haven't had any today..but gosh.. How do I get over being scared about this? And has this happened to anyone else?