Blood clot and cramps possible miscarriage happening

Mon evening I notice bright red blood when I wipe after I pee also had mild cramping. Tuesday morning cramping got a little worst there was a dime size blood clot when I pee, when to the doc to get an ultrasound n a pelvic check because I'm worried I could be having a misscarriage. I was still actively bleeding.... During the visit they told me my cervix were perfectly close and that it's too early to say if I'm having a misscarriage or not. They could only see the yolk sac no embryo yet. I'm supposly 6 weeks and 3 days today, Jun 10, 2015.  
I'm so worried that I'll have a misscarriage is it normal to be bleeding like this plus with bad cramps. From mon til today I'm still bleeding. I actually have to wear a pad now but I don't need to change it every like 5 mins.  n there were 2 more blood clot the size of a dime. 
I have to wait 7-10 days for a flow up and was told to just keep track of my cramping and blood flow. 
I just want to know could this just be something normal and not a misscarriage starting to happen.?  
My first pregnancy so I'm very worried .