For the past day or 2 i've had lower back pain on my right side, along with a headache and diarrhea.

Have you had fever?: This is a very nonspecific constellation of symptoms, but worries me is the possibility of either appendicitis, ectopic pregnancy or a kidney infection or stones. You could have a simple enteritis infectious diarrhea. If you are holding down fluids and aren't having shaking chills or vomiting that's a good sign. If you take a turn for the worse be seen in the ER, otherwise get seen within 24 hours