Brand new Apple Watch Battery Drain!

I have a new Apple Watch 3. Fitbit converter so I bought the 3 Series to make sure it is more durable and useful after a losing battle with Fitbit. It has been great the last month I have had it. All of a sudden a couple of days ago I have to charge the battery around 4pm before I work out or it will just not last. What the heck happened to it? It's a month old! I didn't change anything. In fact I started deleting things, trying to save battery other ways (googled what eats up the battery life) ... I have an iPhone and Macbook so I understand apple products. This upsets me since the device is new I expected at least a day out of a charge!

Any ideas?