All of my saves are gone in dead space

I'm not entirely sure what happened. I log into the game to continue, and I am all of a sudden starting in the opening cutscene. It happened today, at around 9:00 or 9:30 am. This happened before, but I was able to load into my previous saves and it showed all of my saves. This time, however, it showed that I didn't have any saves at all. I don't know what to do and it seems not many people have this problem. I'm on a PC, so I tried to look through the files but couldn't really find anything.  I've already tried restarting my computer and repairing and restarting the game, but it doesn't seem to work. It still shows that I have played for 4 hours and have unlocked several achievements, but none of my progress is there. I've only had this game for a week, and unfortunately have already run into some problems, so any help would be greatly appreciated.