positive and negative pregnancy tests

I’m 6 days late for my period , 6 months pp, the last time i could have got pregnant is around 2 weeks ago. i took 2 line tests that came up with very faint lines, one more visable than the other. Then today i took a digital clear blue but that came up not pregnant. i’m not sure what to think. im aware it’s more likely that the line tests be faulty over the clear blue. I’m wondering weather it’s possible i’m too early for the clear blue to have picked up? which is unlikely given you can test before your period even starts - or if because i tested at like 4pm that could have something to do with this?? just wondering if anyone else has had similar things happen ?