Spotting question, maybe TMI.

So I've been trying since June to get pregnant with my 2nd and this month I tried BBT, didn't work for me because I just can sleep like normal people, did the cm found O to be the last day of my fertile window bd every 24 hours with the hubs and 2 days later my breasts get tender, I'm crying over TV shows an school supplies, but don't want to test early, anyway, af is due on the 18th and today I wiped after i peed and I noticed a very slight pink tint, like if you didn't try and look for it you'd miss it, but its definitely there, and definitely coming out my vag. It's too soon for my period so wth is going on with my body??? I don't want to test too soon and see that I just menstruated early ughhh I hate this. Anyone know why I'd be spotting so soon?