Chances are VERY VERY low. How many words do we have? More than 150,000? What are the chances that someone would actually land upon a wallet with the same words as you have? You have 12 words, if only 1 word out of those 12 is different, it would already be a different wallet. Not to mention the order of the words. etc. If 12 words wasn't safe enough the devs wouldn't have chose it.