I agree. Three months seems VERY early to know that you want to be moving in with someone. I would try taking it slow and having sleepovers before jumping into such a big decision. Staying in a house costs money, and renting an apartment usually puts you in a bind on a lease for a full year. If things didn't end up working out, it could be disaster.
However, if you have faith in your relationship and things continue to go well over time I'd definitely think about moving in. Just don't take it too fast.
I have been living with my boyfriend for about a year and a half now and it's wonderful, but I know that if we didn't have a stable relationship before we moved in and a long time to get to know each other, we may not have worked out as well. There were plenty of other guys at 3 months where I thought to myself "oh I could live with him! I could marry him one day!" but once 6-7-8 months hit, I realized they weren't for me.
Just take it slow, and good luck! It can be a wonderful thing if it's played out right.