Okay mama, that smell is normal for breastfed babies actually, yung amoy na yan parang fermented kasi ng breast milk sa tummy nila, walang harmful bacteria doon so hindi need mag-alala. Pero ang twice a week poop ay medyo konti para sa 3-month-old na breastfed, kasi usually sila dapat mag-poop every few days or kahit daily pa, kaya mas okay kung i-check mo yan with your pedia just to be safe, baka need lang reassurance or may underlying concern na hindi obvious. One of my mum friends' baby din ganyan kaunti ang poop tapos turns out kulang lang sa latch kaya di sapat ang milk intake, pero once na na-fix ang feeding, regular na ulit, so might be worth discussing with your doctor din.