Hi there,
I traveled to Edinburgh when I was about 11/12 weeks.
I wore compression socks, just to be on the safe side.
TBH It's such a personal thing, what might be fine for one person, could be hell for another. My MS hadn't kicked in fully, but was still pretty iffy. The main thing was the exhaustion. Fine for the flights, cause I just slept

but I was only awake an socialising with friends and family for about 6 hrs a day. The rest of the time I was sleeping!
Glad I managed it though, cause it was to see my little sister's first baby and it also meant I could tell my mum and family I was pregnant, in person, rather than on Skype