5weeks 6days ultrasound not seen..

Roz • ✨Age 28. Chemical pregnancy, Oct2014. Pregnant Dec2016. Delivered July2016. C-section. Baby girl, Nurul Fatihah Syifa'✨
I am worried about this.. Got brownish discharged yesterday and not i am admitted in a hospital.. Urine and blood test showed positive results. Went for tummy and vaginal ultrasound, none are visible.. Early in the morning today, another blood spotting. No pain felt. Test results still positive ? 
​What are the possibility? Helpp...