Emergency contraception like Ipill commonly disturbs the next cycle, so a lighter bleed around your period date and a delay afterward are both fairly common side effects, not a sign that something is wrong on their own.
Next Steps
Please repeat a urine
pregnancy test with your first morning urine after another 3 to 4 days, since hCG can take time to build up to a detectable level.
Health Tips
See a gynaecologist soon if you develop pelvic pain, heavier bleeding, or feel faint, so a rarer cause like an ectopic pregnancy can be ruled out.