I'm not sure how it did happen but in my first try, I logged in from both windows and android to sync bookmarks in pc to my phone, but it ended up sync-ing bookmarks in my phone to my pc. Thus I lost all the recently added bookmarks in pc.
Btw there were no any new bookmarks on my phone, just the old ones that I sycn'ed them from my pc in December 2015. So with this recent sync attempt couple days ago, it just reset everthing to what it was in December 2015.