My understanding is that if you miscarry at this point, it would be as if you had a normal period. The bottom line is that time will tell. If you are going to miscarry, this is nothing that will stop it. For now, I would just advise that you take it easy, and see what happens.
I had a miscarriage at 12-13 weeks, and it happened over several days. I started to spot on a Thurs., and finally decided to go to work on Friday, because I figured it would or wouldn't happen -- and I miscarried on Saturday morning.
At the time, the gynocologist told me that my chances of having a normal pregnancy before the miscarriage were always 75%. And after the miscarriage? the same 75%. He also said that when there's an "abnormal" pregnancy (his words), there might or might not have actually been fetal tissue involved.
I was around 36 when I had my miscarriage, and even at that ripe age, I ended up having two more pregnancies, both of which were perfectly, boringly normal and produced healthy children. (yeah, both were "unplanned" and were real gifts to both me and my spouse. Due to age, we weren't planning on having more kids, but we're truly blessed to have them now ! :-) )
so try not to worry (too much). If you feel you need to see a doctor, by all means, call your family physician. But if you do end up with a period, then just wait a while and try again.