For the past two months, I've been tracking my period and both times I had a 35 day cycle.
But this month, I wasn't expecting my period for 18 more days and I'm spottin; my fertility window was actually supposed to start today.
Two days before I started spotting, I had a thick white discharge.
And I've already looked it up and every other site says it's normal if not itchy, smelly, etc.
So that's all in order.
My main issue right now is the fact that I've had regular cycles for two months, that I tracked and now I'm spotting at day 18 of a what I though was a 35 day cycle.
And I fear that it isn't normal, or that I could be pregnant.

Spotting 18 days before your period is due could be from a number of factors.

If its light and doesn't last long, it could be implantation if it happened aprox. 7 - 10 days after ovulation.

Spotting (light -for a short amount of time) can also be a sign of ovulation. I'm not sure what you mean by "thick white discharge" but if its creamy, then turns wet or "eggwhite" in appearance, that's a good sign of ovulation - also paired with the spotting.

Some doctors will say excessive spotting is "normal." Mine did but I pushed him for answers and ended up needing progesterone.

Don't be afraid to push for answers - spotting that far out may not be harmful in your situation but its important to know for sure.

Good luck!