14 dpo line is way lighter than 12dpo line

So I bought 2 frer tests at 12dpo and took the first one around 11:30pm. It was on a 2-3hr hold. Got a clear line that showed up within 1 minute of dipping the test. I waited until this morning (14 dpo) to take the second test. I took it with 2nd morning urine because I forgot the first time. Urine was definitely darker than when I took the first test. The line is barely noticeable and didn’t show up until about the 4 minute mark. Should I be worried? I haven’t called the doctor yet because I wanted to wait until I got a darker line, I believe theirs are less sensitive and didn’t want it to come up negative there. I don’t think I dipped the 2nd test as far down as I did with the first, there was a dry spot on the edge of the test for the first few minutes after the control line was completely there.