Something strange happened 🤔

Hi, i m 9DPO and yesterday i noticed a linea nigra starting to show. I asked DH if he s seeing the same thing, or if i m imaging things and said yes, that he is seeing it too. I had that when pregnant with DD,(10 years ago.)but  it showed later in pregnancy!! I read that the placenta produces the hormone of the linea nigra and its still early to have if i m pregnant. Anyone had the same thing this early? Or do you have an idea what else can cause it? Thanks