The FDA has just approved a new commercially available test called T-Detect to tell most patients whether or not they've been infected with coronavirus in the past. The test will can be taken at home or at a lab, like LabCorp. The test also shows whether or not you've been infected even months after you've recovered. The test detects T-cell activity. During this test, a sample of blood is taken similar to the antibody test. Results usually come back in about seven to ten days.