I'm 18 & have been sexually active since 14 w/ diff partners. my doctor wouldn't let me get papsmears test saying i need to be 21.i feel that's late?

Change doctors: Consult with a different (different gender, age, etc.) gynecologist. You have a right to the care you seek.

Several options: Planned parenthood in some locations will offer such services. You should also consider finding a doc that keeps up with medicine. Pap smears should start soon after the initiation of sexual activity along with screening for asymptomatic STD's.