My period is 5 days late . i have been experiencing diarrhea and severe insomnia since my period was supposed to start . could i be pregnant?

Could be....or not: Diarrhea & insomnia are also seen during nervousness and anxiety which can also make you late or even skip depending on when things peak during the cycle to change hormones etc. If you haven't already, get yourself a home pregnancy test. See what it says. If you've missed periods before or you're irregular then, waiting till next period is also an option. Depends on you.

Get pregnancy test: If your period is late and you have had unprotected sex then you should check a pregnancy test. The headache and diarrhea are probably not related. Make sure you are drinking plenty of water and take a prenatal vitamin with folate (folic acid) if you are having unprotected sex. If your headache and diarrhea persist please see a doctor.