So confused…

Sh

Had my levels checked last week and HCG is rising but not doubling. Figured I would MC any day now. Started to very lightly spot - only small tinges mixed with CM but this also happened to occur after me and hubby had sex. Took a test today and it still looks dark. Not having any symptoms - just slightly tender breasts. No cramping. How long after spotting does MC occur? My other MC were faint BFP’s and my missed MC resulted in D&C.