What Causes Underarm Pain?

Hi, I currently have a cold, my nose is stuffed and my throat hurts. I ve also been having random underarm pain that sort of comes and goes and I m really anxious because I m scared of what it could be. The underarm pain is in both arms, but like I said it comes and goes and sometimes it hurts more than other times. Any idea what this could be? I m 20 years old and to be honest I don t have the best diet. I don t eat at the right times of the day and sometimes I eat the wrong things. I also have headaches (sometimes) but I figure it s from not eating properly. If someone could help me out with the arm pain though I d greatly appreciate it.