I feel like my ex husband may be using me what do you think how would I know for sure?

Ok so he left me back in May and our divorce was final October 1st. It was a very heartbreaking painful experience for me. Anyways about two weeks ago he started coming back around he told me he missed me and really loved me and he was sorry for things he did that contributed to the marriage failing. Anyways, we decided to become boyfriend and girlfriend and try to work things out by starting completely over. I was thrilled I thought I was finally getting what I really wanted but now I am not so sure. At first he was always saying he missed me and loved me and he would kiss me for no reason whatsoever. Now just a short couple weeks later the only time he kisses me is when we are being intimate if he even does then and the only time he says I love you is if I say it first. He had been staying at my house spending tons of time with me but now he has left. He claims he is still gonna see me this weekend but not stay there. I just got this bad feeling in my stomach that this may not be a reconciliation like I had hoped for. I am beginning to feel like he may just be using me until he finds someone else. He has not told anyone we are working on things so it would be easy to keep his options open. He left yesterday and was not planning on seeing me at all but then he came home to find out that his electricity was off and ended up at my house claiming he was gonna come by anyways when he got all of his work done. I don't know how to feel. I don't wanna blow it if this really might work but I don't wanna get used and be a doormat either. How can I tell what his real intentions are?