Ay, 11 days pa lang baby mo so normal pa yan, ang formula babies usually may slower bowel movements compared sa breastfed babies, kaya once a day or every other day ay okay pa rin talaga. But since ito lang ang once tumae mo since today, I'd suggest monitor lang muna if may fever, parang uncomfortable, or bloated ang tummy, kung may ganyan, best to call your pedia na para ma-check properly. One of my mum friends' baby din ay ganyan dati at parang delayed lang ang digestion, pero mas comfortable na after ilang days. Keep baby hydrated, warm compress sa belly kung kailangan, and trust your instincts na pag something feels off, get it checked na.