So basically as the title says- how do i approach the subject and what do i say in the most appropriate language?
I'm 38 + 3 wks preg, so obviously the question of how babies are made, how they get in and how they come out has been raised. Ds is 8, and is quite naïve/innocent of this sort of this (or at least I think he is, he certainly doesn't seem to know anything).
I have basically made a bit of a mess of it so far- and told him (through embarrassment and not really knowing what to say) a sort of partial lie, partial truth about it all. NOT good.
He said where did babies come from and how did they get in there - I was eating an apple at the time i told him that babies grow from a type of seed that grows in your stomach and turns into a baby....'like eating an apple seed' he says...'yes, but it turns into a baby and not an apple tree' says I (groan).
Sort of truth re the seed...complete lie re eating it like an apple seed!
This is now how he thinks a baby gets into mummy's tummy 
'How do they get out without exploding the belly button' he says? 'Does the doctor have to cut the tummy open?' Seizing this as an easy version of the truth I said 'yes, the doctors can do an operation to cut your tummy open and get the baby out'. Cue my cousins CS scar...jobs a good un.
He still has questions though I can sense it- and there's obviously a bit of confusion still- spesh as he keeps asking if boys can have babies, I keep saying that no only girls can have babies and only when they are older, like XXXX (his cousin who is 18).
Having created the tangled web of part truths/ blatant lies...how/what do I now say to him to put things right? I was hoping for him to just learn it from the playground as he gets older, which is a right old cop out I know...particularly with children growing up so quickly these days- I cant leave him thinking that a) I lie to him b) open to ridicule from his friends whose parents aren't quite as bashful and tell their childs the truth.
I remember my mom leaving 'the usbourne book of life' on my bed when I was about 13 as a reaction to me getting my first period, unexpectedly, and without any warning - and hoping that that would be enough to answer any questions about my body, sex and life in general!
I have to say it was pretty informative and did answer my questions for the most part, cleared up some of the myths that I'd heard in the playground, but it wasn't stuff that I didn't already know in one way or another, in a sort or round about way - it was just a bit too late really.
Although I was kind of glad that she had gone about it this way in the end as I cant imagine how embarrassed both of us would have been to have 'the chat'...but then I was 13 YO which is already an awkward age....I cant help but think it might have been better to explain it to me when I was younger and less embarrassed by the notions of body parts at an age where we still look to our parents as the oracles of all known answers to all known questions??