On 6th Jan your ultrasound was 18 weeks and 5 days does this mean you conceived between 9th 12th September?

To determine the conception date based on the ultrasound results provided, we need to subtract the gestational age from the ultrasound date. The ultrasound was done on 6th January, indicating a gestational age of 18 weeks and 5 days. Counting back 18 weeks and 5 days from 6th January brings us to a date between 9th and 12th September, which suggests that conception likely occurred during that timeframe.