Hi, I Took Plan B On Nov.8 And Got My

Hi, I took plan b on Nov.8 and got my period the next week for 4 days and it was a heavy bleed. My expected period was supposed to come the 7th of this month and it still hasn't arrived. Also, I took 2 rapid first response test and they both came out negative and I took those at 6 in the morning. Could I be pregnantes because I have missed my period and I am experiencing alot of abdominal pain and bloating?