I'm on second pregnancy & in both have booked flights at least 10 weeks before flying during pregnancy. Travel insurance usually covers you if you need to cancel for any medical reasons. Enjoy your hol!
I'm booked th fly at 36 +5 and have flown at many times throughout the pregnancy. If you worry about everything going wrong during your pregnancy (particularly when everything has been perfect to now) life will pass you by. And if something does happen at your 20 wk scan, cancelling some flights will be the last thing you will care about.
Thanks all! That's really helped. We have insurance with our travel agent so I'll check we're covered tomorrow morning. Definitely not considering scrapping the holiday, just wondered whether to wait a bit longer before booking