10dpo...extremely faint line


I took a frer yesterday at 9dpo and had a squinter too that was barely visible. Today again, at 10dpo... another very faint line. I also took a dollar store test that was negative. I keep cramping and having lower back aches. I’m scared it may have implanted but wasn’t viable and that it won’t get darker. With my son, it got noticeably darker every day from 9dpo on!

What do you think??