So happy you loved the coat. For future reference, so that you no longer have to get anything tailored, please pay close attention to 'size & fit' tab on the description of each product. For this particular coat we mentioned that it is 'True to size. Size up if you're in between sizes'.
I looked up all of your previous orders and you are a true medium with us. This coat has no stretch at all. It's very true to size, but if someone is in between sizes, we recommend going with the larger size because there's no stretch anywhere.
But since you're a true medium, then you'd be a Medium in this as well.
Hope this helps so that you no longer have to worry about it for future purchases!