3m? Size for a baby

Do you guys think that your average newborn will fit into 3 months? I guess I shouldn't say average cuz I think the average newborn is 6-7 lbs and I was 9! And my whole family is filled with big babies and my baby is measuring a little big since my anatomy scan so don't think it's worth it to buy newborn when I checked the size chart it says newborn size is for babies they weight between 5-8 lbs and I was born bigger than that! So I'm thinking I'm gonna not waste time and money and start out with 3 months! My question is did anyone have a baby bugger than that??! Lol