1 month old baby not sleeping in the day

My baby is 1 month and 5 days, and the past few days after her feeding (expressed breastmilk) she will show signs of sleepiness and we will carry her until she dozes off. But once we put her down in the cot, she will wake up. Or sometimes she doesn’t sleep at all after a feed. Any mommies have similar problem? We suspect she has gas but she burps after feeding. She fusses for a while but when we rock her she will calm down. Is it colic? Or something else? #advicepls #firsttimemom #firstbaby