I Have Had Atrial Fibulation And Am Taking Blood Thinners

I have had atrial fibulation and am taking blood thinners and a pill to slow down my heartbeat and thyroid pills and3 days ago I turned on my side and underneath my right breast area, I felt a pop under there and a jerking sensation under both breasts and it is so sore and touching in the middle of my chest hurts and if I turn it hurts. Do you know what that might be and if its related to meds or heart ?