I think your best bet would be to play it cool for awhile, like another month or so. If you really are sure about how you feel and you can't hold it in anymore, just let it out! There's no reason you should be afraid to express how you really feel. If he's not ready to say it back it doesn't mean your relationship is over. You may find he is still deciding if he is ready to commit entirely to you. If you see him making definitive steps towards a long-term relationship with you, maybe it's time to take the plunge. Just make sure you're ready, like really ready. Congratulations on finding love!
I don't believe there is a certain time you should say it. When you're in real love (not the young little kid love, but the mature kind obviously), you just know. If you're feeling it and you are absolutely sure you love him, then say it. It doesn't matter who says it first in my opinion, because love shouldn't be required to have gender roles. I think you should express your feelings, and if he is not quite sure yet that is okay. I'm sure you'll feel much better when you get your feelings out on the table. And by experience I had been friends with a guy for several months before you started dating. We just 'clicked'. Right when we got together I knew I loved him. He had to go on a trip three days after we started dating, and the first time I was able to get a hold of him I told him how I felt. It turned out he loved me too and we've been incredibly happy together. So go for it! I hope it goes in your favor :-)