I finally managed to come up with a vaguely scientific reason as to why some clinics say no to sex.
Anyway so ... they always say that sex induces labour and they also use this sort of cream to soften the cervix to bring on labour (and for ERPCs). This is because both sperm and the cream contain prostaglandins, which softens the cervix.
So I guess the clinics must be of the opinion that the prostaglandins in sperm could cause a miscarriage. (although there is also scientific research that having sex around ET facilitates implantation - so go figure).
As I said this is vaguely scientific because this was just my recent light bulb moment.
As you all know entire populations have been created by the human species doing all the 'wrong' things, so if you want it go for it, go for it.
Personally I was quite keen to get back on the horse, basically because I want to keep DH happy. I really fancy staying married to him. Also, he'd be a great help in the double nappy changing stakes. I was also a bit scared that if we would fall out of the routine too long, it will be difficult to get back. But I am a bit paranoid about these things. I will litterally go 'we need to have sex now because it's been too long!'.
euro had some massive sexy pregnancy hormones going if you remember, but yeah, my headspace is pretty much filled with things baby (and food) and I occasionally try and make space for sex. ;-)