Should I worry about being 5 days late for my period?

It depends. It depends on your typical menstrual cycle, and whether or not you have been ill or under stress - but if you have been sexually active, a missing period can indicate pregnancy. There are tests available otc that can determine early pregnancy.
Possible pregnancy. This depends on a few things. Being 5 days late could mean you are pregnant. Take a pregnancy test or call your doctor if you are unsure. If you see a pediatrician, call the office if you are unsure what to do. Tell them who you are, and you have a question about your period. Ask to speak to a doctor or a nurse. They are not allowed to share your health information.