It could be either, depending on the concentration of the urine samples and how long it's been since your last positive before now. Has your doctor monitored your hCG levels at all since the d&c? Sometimes,though rarely, a small amount of tissue from the pregnancy can remain after a d&c and cause a delay in the hCG drop. Or your body may have recovered very quickly and you could actually have conceived again. If you are pregnant the test line should get a little darker every day or two (always use FMU for most consistent results). Fingers crossed for you!