Bad indents with first response ?

About a week and a half ago I took 3 tests and they all came up super positive! I was excited! I decided to wait a few days later and got negatives? I think about 2. I gave up, but I never got my period! So this morning I woke up and took a test! Super faint positive but more pink then all my other tests. I’m just super confused on why this may be happening? I haven’t had a period in 4 months since I got the covid shot. I know it may be almost impossible to get pregnant without a period but my last pregnancy I got pregnant when my period was absent for 2 months. Anyway, is this an indent? If so, why are first responses giving so many indents recently? Oh! I also used different boxes of the 6 days sooner test.