7w6d and pregnancy test is not super dark??

Summer

I'm 7w6d and I haven't tested since around 4 weeks. I've had blood done 3 or 4 times and it was rising just as it should. I woke up this morning and decided for the hell of it to take a test (I have no symptoms other then occasional sore boobs). My test line and the control line were both very visable, the test line was only slightly darker then the control? How?! My last lab was around 4.5 weeks and it was almost at 10,000 hcg. My last pregnancy that ended in a MMC my test line eventually got so dark I barely could see a control line.

I did see the HB in my last pregnancy that ended at 7w2d and I saw the HB this time at 6w2d.

I just find it weird that the test line is not super dark. Has this happened to anyone else?