Take action pill delaying second cycle?

I was supposed to have my period on the 26th of November, but I had sex that night and took a take action pill on the 27th (my period did not come on the 26th), 5 days after I took the take action, I got my period which lasted 5 days as usual ( it could’ve been bleeding caused from the pill but idk). Now it is January, I was supposed to start my period on the 6th, I am now 16 days late. I’m not quite sure what this could be! I had 4 negative tests also