6 months moving in together

Hey guys this is kind of a weird question but when is it okay to move in with your boyfriend/girlfriend? Yesterday was my 6 month anniversary with my boyfriend and he has previously talked about moving in together and I never thought much of it but last night he told me to start looking for an apartment and stuff and I think it's getting serious and I mean i love the idea, but I think it's too soon. My mom told me not to do it because he'll end up leaving me. I'm just scared. Please help