I Have Been Having Some Discomfort On My Right Side,

I have been having some discomfort on my right side, just under my breast. At times it seems to radiate to my back. I have been constipated for a couple of days. Thought it might be gas pains. It comes and goes, most noticeable at night when I lay down. Went to an Urgent Care clinic, BP was high, EKG showed slow heart rate, but that is normal for me. Have been taking Anacin a couple times a day to relieve the back pain.