Me and my partner have decided we will probably pay for a private scan this time round (my 3rd baby but his first), mostly because I never would of been able to afford it before and have always liked the idea of seeing it all in 4d etc and to have a (almost) definite answer to the sex.
I am currently 15 weeks. I can't decide if I should go next week, which is when they do the Gender scans from, as I am dying to know what it is. That then only costs around £80 but it's mostly 2d but you get a 10 min 4d freeview included. However I imagine 10 mins in 4d is probably enough.
However if you buy an actual 4d package it says it is best to wait till later for better pictures (Think between 22-30 weeks, depending on which clinic you go to).
I don't know which to choose, the 16 week one is cheaper and means I get to find out what sex we are having, which will be really handy as we are moving and it would be helpful to know if I should bring all my DDs old stuff with us if it's a girl, or if it's a boy we can sell anything girly and not have to move it all for no reason.
But the baby would be so much more developed if we did it later, so it might be better. But it costs more, and we might already know the sex from the 20 week scan if they tell us so it might just not end up happening - might seem a bit pointless.
I also like the idea at 16 weeks of a bit of reassurance. We haven't announced our pregnancy yet due to lots of early problems and threatened misscarriage etc. Where as come 25 weeks or whatever we shouldn't need the reassurance as we should be able to feel baby kicking and hear the heartbeat on the droppler.
Basically, I think I WANT to do the 16 week one, but know others have said it's best to wait, so trying to get a bit more info!