Like AnnieBrooke said, if you were more than a few weeks preg, the test will still be positive. I had a m/c on July 8, at 8w4d preg. I had a test left over, so I took one a couple days after I started bleeding and it was still positive. My hormone levels were monitored and took 5 weeks to return to 0.
I had a m/c on 4th july i was 5 weeks preg, started bleeding on the sunday on the tuesday docs done a test and it was neg.
positive... it takes a weeks to low your hormones :)
Unless it was a really early miscarriage, the results should still be positive for a short time, at least on a sensitive test. However, if the miscarriage was more of a "chemical pregnancy" (i.e., one that began but then ended almost before a period was missed) it might not continue to show up on a home test for more than a day or so.