Pospartum Talk

Hi mommies. It's been one and a half month since I gave birth to my lo. Normal delivery. Mixed feed si baby. Nagpapump ako for like 2-3 weeks. Nagstop kasi umurong na milk ko. Now, napapansin ko kasi na parang sumasakit puson ko. 3 days na sguro. Is this normal? Sa bagong panganak? TIA.