Hi Nicolas welcome to the DHO.
Its all good. Nothing wrong. You didn't create the sensations. You just haven't noticed them until now. Page 52-55 should help with any doubts. I think he is practicing a different technique to you so you may find some parts of the book confusing. However regarding your query, this is almost certainly whats going on and should encourage you to investigate further with confidence.
Best Wishes.
http://www.justbegood.net/Downloads/e-books/In%20This%20Life%20Itself.pdf