terminating rental contract

I have a one year contract that is supposed to end on August 31. I am leaving two months earlier (End of June), and I gave notice of this at the beginning of June. In the contract there is no possibility of early termination, however I don't think the contract has been registered (I never received any notice of this). In other answers I read that, if the contract has not been registered, one can terminate it at any time, but on the other hand the contract could be registered at any time. Can I avoid paying the last two months of rent, at the price of losing my deposit? The deposit (worth less than 2 months of rent) has been paid directly to the owner and I have no guarantees of having it back.