I have constant pelvic pain is that normal?

Probably not. It looks like you are young on your profile. Common sources of chronic pelvic pain might be uti, std, endometriosis, hernia, other things. If you were older, organ prolapse. If more acute, ovarian torsion, ectopic pregnancy, etc. See your gynecologist or pcp for exam and workup. A pregnancy test also probably good idea.
Multifactorial pain. Constant pelvic pain isn't normal. Men, women and kids can have it -- uterus and vulva pain, prostate, and muscles-bones-nerves strains... Sex, abuse, falls, accidents... Infections... Pregnancy and childbirth... See your doctor. Exercise, manual therapy, pt, neurobiofeedback and injections are among the many treatment options. Take care of yourself and get better!
No. No, it is not normal. Ask your gynecologist. There are many possible causes, one cause that is hard to diagnose is pelvic venous insufficiency. Look for an interventional radiologist in your area and arrange a consultation.