How long does HCG stay in system after D&C on 1/27. Had 2 menstrual cycles, took pregnancy tests over 3 days. All faint positive. Seems residual hcg.

Blood test... Its been over 2 months since your D&C. That is quite a long time for the HCG level to stay high enough to turn a urine pregnancy test positive. One way to know would be to get a quantitative HCG blood level and repeat it in 48 hours. That allows you to tell if the level is going up or down. If it is rising, it is most likely a new pregnancy. Its not possible to tell for sure with a urine test.