Plan b help why it’s doing this to my body

Patient: I had my period January 11-16th then had unprotected sex on accident took plan b the following day on 19th no dramatic symptoms then following week the 25 for approximately 7 days heavy bleeding … And now I haven’t had a period since I took a test and it came out negative ….. What is my body doing is it readjusting ? It’s now February 26