Is my cycle changing or what?

I had sex 2 weeks (and two days) ago and I didn’t think about it until after that I was in my fertile window. He didn’t finish inside me so I didn’t want to worry. I figured I would stop having the ovulation discharge like I usually do and then my period would come. Well, I ended up continuing to have the discharge (and actually still have it now) I’ve had indigestion for over a week now, my lower back randomly hurts, I have random mild cramping in my lower stomach, my nipples are sensitive, and they randomly get really sharp pain. I am supposed to be on day 2 of my period but nothing yet, other than a tiny spot on my pad. I took a pregnancy test yesterday (day 1 of missed period) and it shows negative. What gives?