Has anyone had a 4d scan after 31 weeks? We weren't going to have one done because of the cost but MIL has found out about some where that does them not far from us, she saw an advert with the pics and seems really interested in having one but is it too late, on their website it says they will do them up til 38 weeks but I have read on a few websites they should be done before 30 weeks for best results?