what could it mean if he said i love you?

okay so my ex and i were texting two nights ago. and the last text he sent me was ILY, which is short for i love you. i really had no idea what to say so i just said "what do you mean by that" but he hasn't texted me back. could he have just been playing or what. We only went out for a week and the reason we aren't together was because he said he had some things to straighten out and didn't want to hurt me. we talk all the time still and go to see each other and go for walks and stuff. but ever since he texted me i love you he hasn't said any thing else to me. what could this mean. help! i have no idea what to think