Has anyone ever had test lines get lighter?

Here are my tests, from start of the week, then this morning it was lighter so I was sure I’m about to have another miscarriage, and now this afternoon it’s dark again.... do you think this mornings could have been because of dilute urine? Im so confused and this pregnancy is directly after a miscarriage at 6 weeks last month (no cycle in between) so I am already very anxious 😥 I am awaiting my blood test results, will get the second lot on Tuesday because Monday is a public holiday here in Aus... it’s going to be a very long long weekend...