The Universe May Be Infinite

i remember one time riding in a car with you and loren. deb's husband, lawren also has phd. An physics from that other school in cambridge, massachusetts. i asked the two of you about the claims that our universe is infinite. And i think i remember being satisfied with the explanation at the time. But that was a while ago, and i couldn't rehearse that explanationan now. So help me out here again. I if the big bang was 13 point seven billion years ago, and at that time, all matter and energy were like in a point. No matter how fast it's expanding, it couldn't be infinite to day, could it?