I am experiencing pain and discomfort in pelvic area as well as nausea and headaches a few days before my period. Am I pregnant or is it pms?

Check! Best way to find out is to check. The first day after you miss your period, you can take a pregnancy test. Even the dollar store has urine pregnancy tests that are accurate. You can also go to planned parenthood or other free/low cost clinics if you don't have a regular doctor or insurance. Until you find out, act like you're pregnant - in other words, avoid alcohol, smoking, etc. Good luck.