So learnt about this recently after I went to a scan thinking I was 7 weeks pregnant. Turned out I was just hitting my 5th week. After loads of research I learnt that foetal age of completely different to gestational age as conception date can be assumed by doctors especially for those who do not know when they concieved. I always wondered why my sisters had heir babies at writhin 2 weeks (if we are using 40 weeks instead of 42) after  their due date. This means I'm actually 5 weeks pregnant. If your into Google, type in gestational age vs foetal age. Loads of info bout it. Just thought I'd share. I'm sure many people here on glow are already aware. This is my first so everything is new to me 😅. Happy pregnancies Glow worms 😁🍼✌🏿