Neither of my kids have had a room done as they both slept in a basinette in our room for the few months. My sons clothes were kept on the floor of his wardrobe and in a washing basket until his draws arrived and DD's were kept in boxes for a month as we were moving 2 weeks after she was born. I have only just finished decorating their rooms now and DD is 3 1/2 and DS is 15 months and both of my kids are fine.
Don't stress about it. There is heaps of time.