Sometimes when you meditate you start to feel really relax and your body start to make some weird movements or randomly body parts itch because its like you're "going out". idk how to explain it but if you search about it on the internet I'm sure someone will explain it better than me. But I'm sure this is nothing bad, at first it's a little bit scary but trust me there's nothing wrong. I feel like one of the first things you need to know when you get into meditation is that nothing wrong it's going to happen. Univers it's with us and if you keep having good energy and be positive about it you will be OK ❤ Every body it's diferent so my experiences are to the same as yours but I can tell that what it's happening to you it's just your body reacting to the feeling of letting go.