spotting 4 days before period due

I have never previously had spotting before my period, I have light to moderate cramps and I am very light headed, my head feels very fuzzy.

I went for a shower earlier and noticed blood on my underwear sorry for tmi, then nothing for a few hours after then a little more of the brown/pink blood.

any ideas on what this could be? I generally get my period a little late and never have spotting before, period is normally fairly heavy, doctor google gave me 5 different answers :/