Diagnosed positive for pelvic inflammation. Doctor denied to treat until 1st day of my periods. Havng continuous abdominal pain. Should I c othr doc?

Yes. Treatment for pid, if due to std or infection can be started at any time. Your dr. Should have explained his/her reasons, which may be legitimate. But pid is in your body and you have every right to a full explanation for any treatment or treatment delay. Good luck.
Yes. I'm not aware of any reason to delay appropriate treatment of pelvic inflammatory disease (due to sexually transmitted infection). Treatment for pid consists of antibiotics, assuming diagnosis is properly made. Complications of untreated or undertreated pid include but are not limited to chronic pelvic pain, infertility, and/or increase risk of ectopic (tubal) pregnancy. So yes, get 2nd opinion.