I don't want my boyfriend to move in.

[Boobers]

I am 26 yrs old and have been dating my boyfriend for 5 months. in the beginning I really enjoyed his company and we had discussed the possibility of cohabitating down the road. well, now he says he wants to move in with me but I really don't want that anymore. he is a really wonderful person but he just isn't right for me. I only have realized this within the last month or so. how do I tell him I don't want him to move in with me? I have told him I need some time to think about it but he comes back with "I thought you wanted me to move in. is it something I've done?" I don't want to hurt his feelings more than they need to be so I need help. any advice?