How long is 40 weeks anyway?

I've never been great at Maths - but 40 weeks... um, isn't that like 10 months?
Ok, so not every month has the same amount of weeks and so if you spread it all out it somehow works out to ...? I'm confused.

Every time someone asks me how pregnant I am I am at a loss.
At 12 weeks you're finishing your first trimester right? So logically at 24 weeks, that would be 6 months? and then 12 weeks later... at week 36 - Wait! but week 36 (3 x 12) is not 40! In fact that's just about a month early.

Keeping in mind that :

• an average pregnancy lasts 40 weeks (or 38 if you discount the 2 weeks where you're not actually pregnant but have not had your period)
• the baby is due end of July (according to most of the measurements and tests)
• July is the 7th month of the year
• I became pregnant mid-november
• so that should be 7 months + 1 1/2 months = 8 1/2 right? (to which you may add the 2 weeks of amenorrhea to make 9)
  
• which would mean the actual pregnancy lasts 8 1/2 months (but that's 32 weeks + 2 = 34!)
  
• so now that it's May 2nd (week 27) and end of July is 3 months away (+12 weeks), does that mean that we're beginning the third trimester now? (=39 weeks)
  
• and by the way, if you look at the little baby ticker/calendar above, you'll see it says there are 86 days to go - ain't that another 12 weeks!? (is that 3 months? 'cause if it is we're back to my initial question!!!!!)
  

Aggghhhh!

I know that you're probably thinking "Who's counting?!" when all that matters is that things are going well - and the answer is I AM !
I need to plan so that I
a) am allowed to fly back to Geneva
b) arrive in time to have the babe there
c) can do some antenatal aquagym classes and meet my mid-wife
d) have the impression that it's not quite as long as it seems...

I realize the babe will "pop out" (ok I'm trying to be positive and play it down - I am fully aware she will not just "pop out") when she's ready, and that only about 5% of newborns actually arrive on Due Date - but...I STILL WANT TO HAVE A ROUGH IDEA OF WHEN SHE WILL ARRIVE!

Not to mention that:

• we already have a niece who was born on July 22nd 2006 and although she lives in Singapore, it would be nice to have individual birthdates
• without wanting to sound totally superficial - I would much prefer a baby Leo (like hubs and a lot of my friends) to a Crab (although that means waiting a tad longer or at least until after July 23rd!)
  

Ok, well whatever - I just am looking forward to meeting her!

pregnancy baby pregnant 40 weeks 9 months EDD