Can you get pain between your shoulder blades from gerds? I also have a small hiatal hernia

Hernia. The discomfort you get from a hiatal hernia is usually pain in your upper abdomen or chest. If fact, we sometimes think someone is having pain from their heart when in fact it is heartburn from a hiatal hernia. .
Yes. It is called referred pain. Because the nerves that control your stomach come from that area of your back, if you have a problem with your stomach you may feel pain there as well.
Unlikely. Pain between the shoulder blades is most likely related to muscular origins, however some intra-abdominal causes can result in a similar pain but the muscles are usually not sore on exam (eg, pancreatic causes).