Hi, yesterday night while sleeping I kept my hand below my head and tried sleeping to my left and right sides but each time I had chest pain, I also tried sleeping flat but chest pain continued for a while. I had iron deficiency and about four or five days ago I received an iron injection since then I used to have little pain but from the past two days, I don't remember having pain. Is it okay to have pain even after 4 or 5 days of receiving the injection?