Wow! Thanks, everyone for your support after my first post. It's amazing how much everyone is going through and thinkng of others at the same time. Yes. it looks like the m/c rate after IVF isn't higher than natural conceptions so I'll try not to worry about that.
Satya, I can understand your concern but if the toilet frequency continues I'd be doing a test. With my short-lived pregnancy I was running to the toilet often and remember you can have what's like a light period and be pregnant which is why some women don't realise till well along the way. It's a long shot but as I said may be worth checking.
Otherwise good luck with the IVF, I look forward to hearing how you go.