2 months late. wth is going on??

My period is late by another month. I'm on cycle day 69 and I'm confused. The last hpt I took was 3 weeks ago it was negative so I let it go but still no period with no signs of one to come I'm confused. I'm not stressed, no lifestyle changes I'm 17 almost 18 and I am having unprotected sex with my SO. Does anybody have any idea what the heck could be happening? I'm starting to think AF got lost trying to find my house. I am having a thick stretchy discharge occasionally some headaches. My first day of my last period was December 16.