How to fail at fertility charting

We met with Nina in the first week of January.  Now we're into the second week of March, and nary a week of that time has been fully charted.

It's not that I didn't do the reading, or that I didn't spend days debating which chart was the best (that's a whole other post), or order the supplies.  I did great at all the research and shopping (as usual).  However, waking up Heather, not a morning person, to take her temperature at the same time every day, then asking her to lie on her back with ankles in the air while I search for her cervix every night, is harder than giving Amazon yet another portion of my income.

But here's where even my most-beloved Amazon can't help: I started by ordering a small, metal speculum.  Tried once, twice... and couldn't find the f-ing cervix.  Washed it (I at least did that much), put it aside, and, after a few days to recover from the effort, realized we'd lost it.  So after payday rolled around, I ordered a 10-pack of medium plastic speculums, thinking that Heather's lady parts just needed a firmer hand, so to speak.  (The opening parts on the speculum, reader, are called "bills."  Like you were putting the head of a duck in there.  There is just no pleasant vocabulary to be had here-- "mucus" and "speculum" and the ever-appealing "vagina."  That's why I spend so much time fantasizing about baby names.  And, ladies, I am not going to get into a conversation about "vagina."  I listened to The Vagina Monologues on CD and that didn't make the word any prettier.  Let's talk when you've read Cunt.)

New material, new size: still can't find the cervix.  I just can not find it.  Heather claims that she must have one, and she didn't hear otherwise when she got her PAP smear a month ago, so it's gotta be in there.  And it's not like we can't use the equipment-- she found my cervix in one go.
It looks like it's my fault, but who do you look to for a second opinion?  We can't pull in our roommate like we did when Heather got new clothes and I didn't like them.  And, again, I excel at research, so Heather and I were all up on the illustrations in our baby-making bible and hitting Google harder than I did that time I needed to see the video of the exploding whale carcass.  (Yes, I needed to.)
And it's not like I don't understand the pictures and text-- I had an 800 on my verbal SATs, man-- but the cervix is just not where it's supposed to be.  It's like her lady-canal is longer than nature and the charting system intended.  I knew about penises and clits, but are there different sizes of vaginas, too?  Is one better than the others?  I will tell you this: I wish Heather's was wee and tiny right now, because I look like a dumbass.