Has this thing dropped?

I feel weird.
I'm 37w5d or so now, and yesterday I had a lovely episode of throwing up (I
think I've been sick *maybe* 2 times so far, not counting the issues I had
with brushing my teeth a lot earlier on that I've found a way to fix and not
get sick a while back). I've also had MAJOR heartburn the last 3 days
(today is 3d day in a row) Heartburn seems to be in the late, late evening,
if that matters.
I find I'm still peeing as much as always, and it's the same thing - seems
like I really have to go and when I do, it's hardly anything and fairly
often.
I also noticed ever since yesterday, I'm very uncomfortable walking or
standing. I noticed tonight, not long ago, that I kind of walk on my toes,
slightly hunched over. I feel like my stomach is going to fall right off of
my body, so I *think* that could be why I kind of hunch over, and the toe
thing, I have no idea. I kind of noticed this out of nowhere, and I stopped
and basically asked myself why I'm walking around like a lawn gnome or
something. I made a point to walk as normal - flat feet - and it didn't
make a difference. I'm finding it a bit painful to walk normally or like a
troll, but for some reason, the toe/hunching thing seems easier?
I find it slightly easier to breathe the last day or so, but I really don't
know if it's all in my head or not.
Does anyone have an idea of when, about, babies drop? I think I've heard
somewhere that first babies tend to drop real early, but second and so on
tend to drop a lot later. I'm not sure if I heard this about baby dropping
or if it was something else. This is #4 for me, if it matters. I don't
remember this with any of the others.
I feel slight pangs in my lower stomach. My stomach feels rock hard all the
time. This thing is constantly moving, which she has all along. Seems like
she never ever takes a break to relax or sleep. Stretches out ALL the time
straight sideways.
Has anyone had something similar happen? Is it the baby dropping or what?
I'm VERY uncomfortable - heartburn is now an extreme, pain in my lower
stomach on a regular basis while walking/standing, I'm alright to sit or
lay, other than my ribs on the left side kind of hurting, but this is
nothing new. The heartburn and stomach pains and funny walking are, though.
All new as of just yesterday or the day before (or so)

Any ideas of what could be going on? Normal and expected? Kind of driving
me crazy, as it's fairly uncomfortable!

To sum it up...
*Bad heartburn last 3 days, happens mainly late at night
*Pains very low in my stomach while standing or walking
*Walking funny (on toes, hunched over) for some reason, yet walking like
this does not ease the pain in my stomach
*Sitting/laying I feel fine
*Same trend as far as going to the washroom goes
*Got pukey yesterday
*Stomach all around feels like I'm concealing a bowling ball
*TONS of movement, as usual

Any ideas?