What Causes Pain In Back With Abdominal Cramps Before Menstruation?

I have had some side pains and back pain and adominal cramps. I was due to start my cycle but have not. I tried a home pt and it was negative. I also have been gagging and really nauseated. Does that sound like it may be a kidney infection. If so would the infection cause me to feel menstrual crmps and miss my cycle?