Weight gain

Got my 28 weeks check up and I lost almost 1kg of weight. Scan result says my baby is 1141g but im losing overall weight instead of gaining. Is it normal? Who else has the same experience as me? My pre pregnancy weight was about 68ishkg.. now im 69kg++.. im 30weeks now and i think im still losing/maintain my weight but i can see my tummy is getting bigger🤔