Used?

Hey everyone,
For the last month i have been meeting up with this bloke about once a week, we havent slept with each other yet ( done everything else) but before i do, i want to know whether hes using me or not.
He asked me did i want a relationship at the moment and i said no, he said neither did he but we will see how things go and it might develop into one. I asked him if that was what he wanted and he said he doesnt know, maybe. The other day i told him that i aint a slag and that i dont just go back to anyones house and he said he knows, and that as long as we are both having fun theres nothing wrong with it.
Hes also said to me that he doesnt sleep with people unless in relationship, which i think is a good thing and i agree.
At the start of things, i did just want a bit of fun, but now im thinking i want a little more, nothing serious but something more that fun ( If you understand). Im thinking though that as soon as we have slept with each other he might just f*** me off basically?
How do i know whether he is just using me and what do you think i should do?
Hes told me that unless i get bored of him he isnt going to get bored of me etc. Sorry for me ranting on its just i cant really talk to anyone else about it properly.
xx