implantation bleeding period late almost 2wks neg hpt

I’m currently not on any kind of birth control my last period started on oct 18 and lasted 5 days. I had unprotected sex with my partner on oct 30and 31st. Those were two fertile days and I was supposed to ovulate between nov 1-4 (according to different apps). So my period was supposed to start on nov 18. A couple days before I started getting brown and pink spotting but figured it was an early start to my period. I also had very light cramps, and only had maybe a tablespoon of red blood come out and for the following 6 days it was very light spotting on and off that maybe would’ve filled up a regular pad.i took a couple pregnancy tests and they were all negative. Now its December 3, still no period. My periods are always on time and are always heavy with severe cramps. I don’t know what’s going on and I’m terribly confused.