When do you recommend I take my FRER? (Please read description)

I got some faint lines yesterday and this morning at 8/9DPO with sensitive strip tests (10mui). I want to confirm with a FR (which I believe has the same sensitivity?) but know the brand has been iffy, to say the least, when testing early. My AF is due tomorrow (10DPO) so do I test then? Or wait a bit longer as most people wouldn’t start their period until 14DPO, so that’s when they’ll be most accurate? Or doesn’t it matter since I already have faint lines on the strip tests?

HELP a girl out! I want to get a strong positive so don’t want to test too early and be faced with a questionable result!!

TIA