Suggest Treatment For Heart Palpitations In A Person With Thyroid Disorder

I am a 58 year old female with a history of a partial pancreatectomy about five years ago...not diabetic. Then one year ago, I had a partial thyroidectomy. One small spot of cancer found. Only treatment is Synthroid 75 , regular checkups and ultrasounds. My thyroid levels have bounced up and dow since surgery. My last TSH was 5. The endocrinologist wants me to stay at 75 because of my history of palpitations. I have had palpitations for the last six years and one episode of a fib that landed me in the hospital. I was on Sectral about four years and have been off for a year and a half. I was also on multaq for about six months prior to going off the sectral .. Thought it was going to kill me. I have done quite well. Until two weeks ago. I started having palpitations. My EP cardio has me on a pill in the pocket, I am suppose to take one Sectral if I am in a fib. I took one on Dec 23rd and one last night. It seems at night when I lay down it kicks off premature atrial beats. Sometimes they are frequent. Beat mis beat beat miss beat several times and then miss again. Sometimes every other beat, sometimes two beats sometimes every fourth beat. No chest pain or shortness of breath. Think I am not tolerating a TSH of 5. Is it safe to wait till Monday to call my doctor ? Thank you !!