Does it give you an estimated due date? It's a lot simpler to just put the e.d.d. into a conception calculator and see what it gives you for an estimated conception date, than to try to puzzle out GA(AUA) and the like, especially once you're at your 24th or 25th week. Babies grow at different rates, and nobody should use a 24th-week ultrasound to try to decide anything about conception.