Should I ask him what his intentions are?

This guy that I work with broke up with me about four months ago. There weren't any hard feelings that showed up between us. We did and still do act like friends. Recently he's been acting REALLY friendly towards me, smiling all the time and offering to help me out with things. He has also been texting me more often. Last night he texted me again. He asked me if I was at work, which I was. And I asked him if he needed me to check the schedule or something for him. He didn't respond, which has happened before. Should I text him today and ask him why he wanted to know if I was at work? I don't know what to do..