Aw, exciting! 23 weeks is still a bit early para sa 100% accuracy, pero ang ultrasound tech usually nakikita na niya kung ano ang gender by then, it really depends kung gaano clear ang positioning ng baby mo bukas. A few of my mum friends got it right at 23 weeks, pero iba-iba talaga sometimes, kaya laging may chance pa rin na surprise pag birth haha! Just enjoy the ultrasound and ask the tech kung clear ba talaga bago mo i-announce