New born clothes

Hello! I’m due in 3 months time so I would like to start shopping for clothes. What size should I get those clothes in? 6M? 9M? Will they be too big? My previous check shows that Baby is at 75th percentile....... it’s my first child so I’m really unsure. But people advised me to not buy NB or 0-3M because they definitely only fit once. Thanks in advanced