The i-pill works by delaying ovulation, so it commonly shifts your cycle for one or two months after you take it. The withdrawal bleed you had first was likely that delayed period. This second episode, lighter than your usual flow and without pain or cramps, is most often just irregular spotting from the hormone disruption, not a fresh period.
Next Steps
Take a home urine
pregnancy test now to be sure, since the i-pill isn't always effective and an unusual bleeding pattern can also come from a miscarriage or an ectopic pregnancy, which a doctor would need to rule out. If the test is negative, track your next cycle, since periods usually settle back within one to two months.
Health Tips
Please see a gynaecologist if the bleeding becomes heavy, lasts more than a week, or if your cycle hasn't settled after two months.