Test lines getting lighter :(

Hi everyone. I got my first positive on the 3rd April with an afternoon wee and there was quite a distinctive positive. I was 2 days late, I did another yesterday which was still positive but slightly lighter again with afternoon urine. But I have done two more with my FMU and they are even lighter. I had a miscarriage in 2021 so in my gut I’m telling myself I’m loosing it. Has anyone else had tests get lighter but the pregnancy was okay? I suppose it’s just a waiting game now :( The bottom two tests are what I’ve taken this morning.