How soon after missed period should I wait to take a clear blue digital test

I had a faint positive test on Tuesday night . I took a clear blue the next day and it said "not pregnant" . I was supposed to start today but I have no sign of AF . I have mild cramping and a lot of watery CM . And I wanna re test but idk if it's to early for the test I have bec I heard they're not as sensitive !