Pregnancy symptoms with iud!!

I got my mirena iud inserted september 5th, 2018. For the past 2-3 weeks I have been feeling pregnant. It started with my period stopping for a day and then 2 days with pink spotting then it stopped again. And I havent had my period since then. For the last week I have been feeling crampy, nauseous, fatigue, weak, drained of energy and slightly sore breasts. Has anyone had this problem and were you pregnant? I took a test just now and it was negative.🤨