Pendulum will give a lot of 'false positives' at first. Be sure you're testing negative answers and random questions (Is it friday/sunny today?) to check calibration. Water with increased electrolytic content can aid in facilitating an increased conduction of energy from the Crown down through towards the arm to the palm vortices. Water can be programmed prior to drinking to also aid in strengthening the connection to the true Self.
If you have a slight cranial pressure that will likely be an expansion as your Crown is expanding to accommodate a higher spectrum of frequency. This usually occurs in the beginning when you start using the pendulum/dowsing and accessing higher functionality that way.
Edit: Ask your personal guide to protect/guard the 7th Chakra channel when asking questions, especially at first, only allowing your source group to come through. This will aid in removing the possibility of other entities responding which may not necessarily be of 'benefit'.
If you have a slight cranial pressure that will likely be an expansion as your Crown is expanding to accommodate a higher spectrum of frequency. This usually occurs in the beginning when you start using the pendulum/dowsing and accessing higher functionality that way.
Edit: Ask your personal guide to protect/guard the 7th Chakra channel when asking questions, especially at first, only allowing your source group to come through. This will aid in removing the possibility of other entities responding which may not necessarily be of 'benefit'.