Blood clot around the sac

Hi, went in for a 6 week ultrasound as I had a miscarriage in September 2013. There was a heartbeat at 115 bpm which the sonogropher said was normal. There was however a small blood clot around the sac (outside) which the sonogropher told me was common and that I may have to take extra precautions. Showed to the doc who told me to take complete bed rest for 3 weeks and that the fetal heartbeat was a little slow..checked the internet which kinda told me that at 6 weeks 115 bpm is normal..also so far there has been no spotting..just wanted to check if anyone else has experienced the same or has any knowledge? Many thanks!