Opinions on my HCG lines?

I’m 5 weeks 4 days, 16dpo. My HCG lines were getting darker, and the OPKs I took for fun were super dark too. But this morning it looks like my HCG line (green tests) is the same darkness as yesterday (I’ve been scrutinizing it), and my opk test line got lighter than it was a few days ago. It worries me even though I know it’s not “a reliable way to measure HCG”. I still liked seeing the lines get darker.

Has this happened to anyone else? Is it normal? Thanks, I’m just nervous. I really want this baby.