There are many sources of information, even by a simple google search, that indicate headaches as a side effect with hgh use... you are not using a high dose, so it would not be on the common side but everyone is different and so it is certainly possible, especially if you are not using a certain pharmaceutical grade compound, which it sounds like you are not sure if you are or not...
Now the warm feelings and feeling off, im not too sure of the cause... certainly with a new compound into your body it could cause you to feel off but playing around with any steroid or hormone that you are not certain of the authenticity is playing with fire and even with pharmaceutical grade, there is obviously still the likelihood of some sort of side effect occurring.. if you find it is not agreeing with your body, then it is simply not for you and you need to listen to your body response and decipher that for yourself