Wow, this thread has been busy. Congratulations to everyone having 20w scans / reaching milestones! It's so nice to read positive messages and I'm so, so happy for each and every one of you.
AnneLovesGilbert hope you feel better now and you managed to get some rest. Just try to eat little and often (good diet suggestion from whiteonesugar) and keep up the fluid intake.
Miami81 dancing baby made me smile, having a little fun in mummy's belly. Hope you managed to get some sleep after.
NoCatsHere hope the next fee weeks just fly by and the baby kicks every single inch of you 
whiteonesugar congrats for reaching another milestone! I agree with what you're saying, best to do whatever provides some reassurance and can get you through these weeks. Keeping everything crossed for your early scan.
Iswallowtoothpaste how do you feel? Don't worry about symptoms coming and going, it's normal at this stage.
A little update from me: I'm 10w today and just before 9w, all my symptoms (and I really mean all) disappeared overnight. Both me and DH spent 5 days just going crazy and preparing for the worst. Poor DH was so upset, more than I've ever seen him, so we decided to have a private scan at 9+2 to end the torturous wait. Lo and behold, the baby was wriggling and everything looked as it should. My DH pretty much did a happy dance in the scan room
The sonographer told us that it's a big no-no to listen to the heartbeat in early pregnancy as the heat generated can be bad for the baby. I wasn't aware of this. Made us paranoid, as the last time we had a private scan at 9+5 during which we listened to the heartbeat and I miscarried 4 days later. I did some research and a lot of sonographers, all over the world, say that frequent scans, especially in the first trimester, are not recommended (unless there's a medical reason for them). They also say that listening to the heartbeat is worse. So we'll definitely wait patiently until my NHS scan at 12+5. Booking appointment this week, one step closer...