What just happened?-gctid8087

Hi everyone, I'm a relative newbie to the world of prostate massage and am hoping someone can explain a couple of things to me. First a little background. I've been married for over 30 years and until recently could not imagine buying and using a prostate toy. With my wife's blessing, I purchased the Aneros Eupho Syn. I've used it 6 times now, twice while having intercourse with my wife and the other 4 times solo. The first time using it solo, there was some pre-cum oozing out but that was about it. The second time I felt a couple of slight tremors from deep inside, but that was about it and ended up giving myself some manual stimulation which really seemed to empty my prostate. The third solo event I felt wave after wave of pleasure which lasted for a couple of minutes. The last time I used it solo I felt the same waves of pleasure, but also had a fairly intense dry orgasm. In reading some of the other posts on this forum, I realize I'm fortunate to be this far along in just a few attempts. But, i don't quite understand what to expect next? And even more confusing is what happened early this morning. I was laying in bed half asleep, on my side in a similar position as when the Aneros is inserted, when I started having a few of the waves of pleasure kind of running through me. The weird part is I did not have the Aneros in and hadn't used it in a couple of days! So, what just happened? Is this normal or is this something to be concerned about?