My friend hasnt had a period in a month and hasn't had any sexual contact what is wrong. she is freaking out and is having back pain and cramps.?

Missed cycle: Cycles can be missed for several reasons - stress, pregnancy, new female in a close environment (ie work, study group, home) when a cycle is missed it can cause this type of pain until the next one occurs. But if she were my patient i would still check a pregnancy test - sorry but the "freaking out" would make me more suspicious.

Don't freak out: Her period is likely just a little late. Back pain and cramps are a sign that the periods is on the way. Talk to your primary care and they can give you advice or information to ease your concerns.