Very faint line on first response

So I took a first response last night at about 12am, very faint line (read within the 3 minutes, came up at 30 seconds). I took another one this morning when I woke up (I did PU early this morning at 5am so not truly first morning urine) and there is a very very very faint line which is not as dark as the one 8 hours prior? Has anyone experienced this?

I've been using the strip test cheapies and always getting BFNs so not sure...

I am 9dpo, AF due in 4 days. 3rd cycle.