Faint line then next day negative

I took a test with first response yesterday, it had a vfl but it was pink. It was the first time in over 9 months I’ve seen ANYTHING on a test. Today with fmu I took one and negative. I’m assuming this would be a chemical?🙄 im not really upset, whatever happens happens we weren’t supposed to try this month but continued doing what we do because we been trying so long why would it happen the one time we “don’t want” it to (of course deep down I do want it but it’s one of those things). My period is due tomorrow