Hello,
Thanks for writing to us.
If you have gotten NEGATIVE test recently, then possible pregnancy has been ruled out.
In absence of pregnancy, other reasons of irregular late period may be due to PCOD,
ovarian cyst, hypothyroid state, over weight/ extreme loss, extra mental stress or anxiety, emotional upset,
eating disorder, high prolactin.
Here, I suggest you to undergo complete hormone profile (LH/ FSH, serum prolactin,
progesterone, thyroid, DHEAS,
testosterone etc) and pelvic ultrasound scan.
Review with test results or you can consult with local gynecologist. You may require hormonal pill to induce period.
Maintain genital hygiene, control body weight. Good luck.