Faint lines on FRER, but negative on digital tests. Any experience?

Ive been taking tests now for about 4 days. First response on 1/19 after missing my period by 2 days, got a vvv faint squinter line. 1/20 came back slightly better. Definitely more visible. However, I took a digital clear blue and it said negative. 1/21 and 1/22 are both the same. I don't see any change in the lines, but they are definitely there. I am coming up on a week of missed period. Digital test still says negative. I sprung for a blood test and im getting one today from LabCorp, so I'll hopefully know more tomorrow. But has anyone ever had a similar experience?