My 1st pregnancy got the faintest second line, which - like you, stressed me out! But, I was pregnant - and it was a flawless pregnancy.

A faint line is a positive - next step is to get the blood work at the doctors.

Spotting is normal in very early pg - at this stage with all 3 of my pgs I kept checking that AF hadn't arrived because of heavy CM (which was brownish too).

Good luck with the dr.