Marley, I had and still have exactly the same problem over the last month
Juleika woke/wakes constantly at night, about every two hours and I became a monster as of sleep deprivation (poor OH!!!)
like you, I wasn't entirely sure why!
firstly, I thought she wakes as she is itching 'cos of the rash she had! well, the rash is gone now and she is not itching anymore
secondly, I thought she got used to waking up and having mummys boobs just right under her nose, as we had her in bed with us constantly since she had the rash!
and the other two options what I am thinking of, are that during the day she isn't eating enough as she needs to absorb everything around her + she is physically more active, or she really is ready for weaning as her appetite seems to be huge nowadays
sorry, I am not of help at the moment as I also still try to figure out what exactly it is!
I just know, that Juleika is waking constantly during the night since about a month, so possibly no growth spurt?