Hi,
Being a little headachey and a lot constipated would count as die-off in my books. Remember most of the critters are microscopic, so you won't see them in the toilet bowl waving up at you. Anyway, it does sound like you are experiencing some die-off.
I am on day six, and so far the only unusual things have been a bit more tireness than usual, and 2 MASSIVE GB attacks, but I'm not sure if that is related to Humaworm or the fact that I did a LF just before I started and could have stirred things up. RG made me a batch to target liver flukes, so maybe that's what it's doing... I'm going to ask some the others.