Sleep Regression?!?!?!

For a week now, Lilly has been waking up at night. 

Before I continue, please let me go on record and say that I know I shouldn't complain because we really have had such an easy time with sleeping.  BUT.  As a result of aforementioned easy time with sleeping, I am not used to sleep deprivation and I am here to tell you that it. sucks.

I'm not really sure what's going on.  We've had the occasional "wake up during the night" here and there, but it's never been consistent and I've normally been able to pinpoint the cause: teething, sick, super dirty diaper, etc.  This time is different, because I just can't figure it out.

I was worried at first that the wake-ups were due to Lilly being hungry.  I know what you're thinking: how could a child with that many rolls possibly be hungry?!  She is obviously not malnourished.  I think I mentioned in a previous post, though, that my supply has taken a huge hit as of late.  I thought it was stress, or maybe pregnancy (let the record show that it is NOT pregnancy), or any number of things.  On the days when we're together and Lilly nurses, it's not like she's hungry after nursing - but when I pump, I'm not getting NEARLY as much as I used to.  Any lactation consultant or doctor will tell you that what you pump is definitely not indicative of what you're actually producing when a baby nurses, but it's still been hard not to worry when I was used to getting a certain amount from pumping and it just dropped seemingly overnight.  Most work days, I don't even pump enough while at work to make one bottle for Lilly, so we've had to dip into the freezer supply some.  I'm more thankful now than ever for my early oversupply and our freezer stock (which we hopefully will not deplete over the next two weeks due to all of our upcoming travel).  Anyway, I digress, I don't think it's even a possibility that she's waking up due to hunger, because she goes to bed not too long after she eats solids for dinner (and she has been eating a LOT of solids).  Also, three times this week instead of nursing I gave her a bottle just to make sure my low supply wasn't starving her.  She still woke up.

When L wakes up, I nurse her.  I'm not sure whether you're "supposed" to do that, but it's what we do.  I know she's not hungry, I think it's more of a comfort thing, but it's really just easier that way because she is up and down in less than 10 minutes (Me on the other hand, not so much.  It takes me FOREVER to fall back asleep, hence the sleep deprivation.).  We tried letting her cry it out a little on Friday night - we used some variation of the Ferber method - but we are suckers and only lasted an hour.  After the hour, I went in and got her and nursed her and she was literally back asleep in 5 minutes.

Anyway, so now I just have to figure out what is going on.  I think she has a few more teeth coming in - I can see two on the top that haven't yet broken through, and she's back to drooling up a storm and chewing on everything in sight.  Other than that, I guess it could be anything.  She hasn't really eaten anything different, so I don't think it's gas.  She drinks a lot more water now so she has wetter diapers but I don't think that's it, either.  I'm pretty sure it's not hunger.  Her room for some reason gets pretty chilly at night but she's never cool to the touch - we dress her in PJ's and a sleep sack (she's not hot/sweaty, either).  It's just so strange to me that whatever is happening is happening now, when it hasn't happened before.  In addition to not knowing what's wrong, I feel like I'm not sure what I should be doing.  By nursing her to help comfort her and calm her down, am I teaching her that it's okay to wake up in the middle of the night?  Should I be trying to let her cry it out?  I realize that it's only been a week, and I'm hoping this is just a phase, but you just never know.

Has anyone else had issues with this?  Any advice/suggestions would be greatly appreciated!

Sarah