Is it too early?!

I am currently dating this man and it’s been 4 months. Things are going well, we’ve met each other’s family and he treats me right. He met my son as well and they get along fine. We have little arguments but we always fix it with clear communications. He kept mentioning how we should move in together since we are always together, so I told him he could move into my apartment since it was bigger than his. He said he wanted to give me a promise ring prior to him moving in, just to show he’s serious, ready for commitment and he has no doubts about us. I’ve made mistakes before in my past and does not want to get hurt. Please I need some advice is it too soon? Is it too good to be true?!