Well today i tried the pendulum for the first time after I meditated. I asked it a couple of yes and no questions, and it literally jerked from the bottom where stone is when I suddenly changed question to change its direction to the correct answer plus every time I said thank you it would stop suddenly. Every answer was correct and it kinda freaked me out but I wasnt scared. I guess i didn’t think it was going to work my first time.
My question is …should I be concerned? What controls it?
I just got an awesome book, Pendulum Magic for Beginners. Haven’t got around to reading it yet but it looks like it should answer your questions. It’s by Richard Webster.
I’m new to pendulum magic myself, so I hope this helps.
I wouldn’t be concerned if it was me personally.
I think you and this pendulum have a strong connection to each other. It’s awesome to have that early on in your journey together.
“By responding to your body’s own energetic field in conjunction with your higher intuition, it provokes jerk reflexes in your arm and wrist that allow the pendulum to move in certain direction to answer your question.”
"This reflex is called ‘Ideomotor reflex’ "…
These quotes are from A Little Bit of Pendulum by Dani Bryant
Of course there is so much more that goes into it but I hope this helps a little but for you both 
@sandra3 and @Amethyst
The connection I have with my pendulum Rosica is one of my favorite relationships I have(not meant to sound like a creep lol).
Like the beautiful @janelle said, you have a great relationship with your pendulum. Crystals have energy and working with your energy and your intuition, it’s so strong that it jumps. Nothing to worry about.
It helps me @janelle! Thank you! I’m getting a pendulum and a pendulum mat in tomorrow so I’ll be able to start working with it.
Just like Janelle said above, there are a few different factors that can go into what makes the pendulum move. Most likely it’s your own subconscious that already knows the answer!
It can also be your Higher Self that speaks through your own intuition.
Or your brain that just needs a tool to make the answers heard. For example, if you get a pen and start writing (aka “free writing”) you’ll notice that lots of information will suddenly come out from your subconscious mind if given the chance.
Congratulations! I think I’d feel freaked-out first time as well. Need to get a pendulum.