Line progression

Hi girls, so I found out im pregnancy at 9dpo and had some clear positives by 11 dpo however im now 13dpo and I took a test and the lines are still very much there but not as dark as they were 2 days ago. Im so so worried as I’ve experienced a few losses. I did take the test in the early evening where as before it has been late morning/ early afternoon. Could this be why? Im just so worried, has anyone had this before? I also did opk tests and one had a strong postive where as the other one had no line at all.

Thanks in advance x