Faint line on cheapies but clear with other brands?

Anyone had a case of getting only faint lines on cheapies but when changing brands they had clear lines?

I’ve been having faint lines on cheapies ordered online, being 15dpo I’m thinking it’s a chemical but still have some symptoms (nausea and bleeding gums) so maybe I’m just trying to keep my hopes up.

Also LH is still high but I know it can also be before af comes

If anyone had this case with cheapies let me know !