Hi, Thanks for the query. Sometimes in early pregnancy spotting can be seen due to many causes like implantation bleeding, increased vascularity etc. For more details :http://srsree.blogspot.com/2013/06/causes-of-bleeding-per-vaginum-other.html Usually by 6 completed weeks heart beat of the fetus can be visualized. But sometimes because of wrong dates etc problems, heart beat may not be seen in 6 weeks. So, better to repeat the ultrasound after 1 to 2 weeks. They have given progesterone injection and tablets to you. Progesterone is the hormone that helps in maintenance of the pregnancy. So, no need to worry. Better to prefer natural micronized progesterones as per as possible. Take care.