Miscarriage ...possibly pregnant again?

Nicole

So on December 18th I went in to the hospital due to cramping and heavy bleeding and found out I was about 5-6 weeks pregnant. My hcg level was in the 6000s and then about 5 days later I went to my primary and my levels showed 141. I took a pregnancy test about a week ago and it looked negative to me. I took another one tonight and got a positive on a Walmart test not blazing positive but could definitely tell... after that I took a clear blue digital test that said pregnant. Is it possible to get pregnant that quick after a miscarriage? Or could this be just left over hcg from the miscarriage?