When can I expect to get a negative test after miscarriage?

I started my miscarriage on June 29th when I started bleeding, I passed everything on July 4th, and am almost done bleeding now. I am patiently waiting to start trying again for my rainbow baby. I took a pregnancy test yesterday to see if it would still think I was pregnant from my hormones. Unfortunately, the test was positive. I haven't had sex since my miscarriage so I know I'm not pregnant. HELP! When can I expect to be able to get that negative test so that I can TTC again!?