Sayang, lower abdominal pain macam ni kena check dengan doctor lah, especially kalau dah berapa lama or getting worse, tak boleh main-main. A few of my mum friends went through similar isu and ternyata banyak je sebab dia, dari period cramps sampai other things yang perlu proper check-up. Jangan tunggu lama, better safe than sorry kan, apatah lagi if you're breastfeeding or recently postpartum.