Last 2 months i have bleeding between periods and pelvic pain, very hurt and this month only pelvic pain between period. what does this mean?

Many possibilities: There are several possibilities here and many are potentially serious. At your age (19), I would worry most about pelvic inflammatory disease (PID), which is an STD problem, assuming you're sexually active. But endometriosis, tumors, or various hormone problems are possible. See a doctor ASAP -- do it immediately if you have fever or abdominal pain is bad. Good luck!