Freaking out - line slightly lighter?!

I am 4 weeks today so very early days. I first tested positive at 8DPO and test have been getting darker. Nice and dark at 11DPO and tested again today at 13DPO (4 weeks since LMP) and it is slightly lighter. Today’s test was from a different box. I have also continued temping and I had quite a drop (still well above coverline) and some sharp pains yesterday which may or may not have been normal. I know I need to stop testing and temping but with 4 prior losses, my anxiety levels are sky high.