CALLING ALL LADIES WHO HAVE HAD MISCARRIAGE

I had a miscarriage onChristmas <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> at approximately 6 weeks. On Jan 1 my levels were down to 81. January 9th I went in for an ultrasound and a hcg test, to confirm my uterus was clear (everything had passed) and to confirm my levels were going down (went from 81 to 31) it’s now Jan 21 and I lve noticed little symptoms but only had unprotected sex once about 2 weeks ago. Could this be left over hcg or I could I be pregnant this soon after miscarriage? Any response help. Thank you!