positive after miscarriage

hi all, I recently found out I was pregnant, but on Thursday 3rd August this year it was confirmed via blood test that I had miscarried at 5 weeks. I was told my hormone level was down to 9 and I was taking negative tests straight away. for closure I continued to take negative tests over the following week. anyway, my husband and I have started ttc straight away again and this morning I got a positive test. this is only 2 Weeks after I had my miscarriage. I don't think I have any hormones left over in my body but I didn't think I could get pregnant this early after miscarriage?