Preg tests lightening

Feeling bummed my FET looks like it failed. Anyone else deal w tests that are getting lighter? Took one yesterday at 8dp6dt in afternoon and got a light line but definitely there and made me hopeful. Then this morning took test w FMU and it was barely visible. It dried darker but I still am convinced one just implanted and now isn’t progressing. This isn’t my first time w this happening but it’s so frustrating. Plus I have a dull pain around right ovary which is just bothering me and making me fixated on this whole thing