Hi mama, ang setup mo parang confusing kaya I really think you should see your OB soon para ma-check properly, two months without period pero negative tests multiple times is something a doctor needs to look at in person, especially since you're still breastfeeding your 4-month-old. It could be delayed period from postpartum hormones (kami ng kaibigan ko may ganyan pa months after birth), irregular cycles habang nagpapasuso, or something else na kailangan i-rule out ng doc, pero hindi mo dapat guesswork lang yan. Better safe than sorry, bestie!