In the dark

I'm seven weeks pregnant. Last week I had some light spotting and the doctor put me on progesterone because they said my levels were a little low. Yesterday I went back because I was having a little more spotting and when he looked at my ultra sound he said they weren't seeing what they should be at this point but he didn't want to write it off as a miscarriage until the blood work came back. My blood work said my hcg levels were rising and they looked good but they still don't know why I'm spotting. They scheduled me for another sonogram next week and told me the one done yesterday wasn't clear enough to say anything for sure. It was my first vaginal ultra sound and it was very uncomfortable for me. They sent me home told me to stay in bed and to monitor my bleeding. I haven't had any spotting today but I still don't know how to feel about this. I'm very young this is our first pregnancy and im very scared. Does anyone have any advice? I just sit here all day and think the worst. It's going to be a long week.