Waiting for Nature to take its course

Since I cannot get in to see my doctor until Friday since he is out of the country, here I sit waiting for nature to do its thing. I should be 11 weeks and 2 days but according to my ultrasound yesterday they are dating me at 7 weeks and 5 days and there was no heartbeat and no fetus. I know my dates were correct as we had been tracking my period. Last night I started getting blood when I wipe but it is still dark and sometimes with bits of tissue or stringy clots. I have lots of pads readily available. How long can I expect this to take? I have some cramping but it is not severe. Is it worth it for me to bother going back to work this week? I do not know what to do at this point but to sit here and wait for the inevitable to happen. Any advice would be appreciated as we would really like to be able to move on from this and continue TTC. Thank you and sorry for the long post.