Curious with faint line

This is just my understanding. The pregnancy test strip measures the presence of the hormone human Chorionic Gonadotropin (HCG) in human urine, which helps thicken mom’s uterine lining to support a growing embryo and tells the body to stop menstruation. HCG level usually peaks at 8-12 weeks and start to decline after that. It usually plateau during the second and third trimester. That explains the faint line. By the way I use the same test strip too, haha!

this is the "hook effect", caused by very high hcg levels (normal at 13w) which skews the test reading. simply dilute your urine with alot of water & you'll find a much darker test result.