21old male, having discomforting pelvic pains, took doxycycline for 7 days and symptoms cleared then symptoms came back after 2 weeks. just finished taking my 2nd 7 days dosage of doxycycline and the pelvic pain still present please what is wrong?

So much more information is needed. This is not the ideal forum to obtain a meaningful solution to your issue. Please see a physician in person who can refer you to a urologist.

This depends on the cause of the pain, i.e. what your doctor is treating you for. Prostatitis? Antibiotics often don't help, but if they do, up to 6 weeks treatment is needed. Maybe that's why your symptoms improved then worsened again. If not seeing a urologist, ask for referral. If not prostate or other genitourinary problem (e.g. intestinal?), a gastroenterologist and/or surgeon. Good luck.