Hello,
Thanks for writing to us.
Most women get their period within 4 weeks after stopping Cerelle pill. You have quite chance of being pregnant as you involved in unprotected sex on pill free days.
It is too early too confirm pregnancy. I suggest you to repeat the test after 1 week (i.e 4 weeks after pill free days).
Blood test for beta-hCG is more reliable in your case.
In absence of pregnancy, other reasons of late period are 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.