Regurg issue in Imerial pueblan

[RAD House]

I recently bought an Imperial Pueblan milk snake(75% Pueblan milksnake and 25% Cal Kingsnake) and I am looking for some advice. I fed a few days after I received him to give him a little time to settle. He took the small pinkie just fine. I didn't see him for five or six days as I was out of town. When I got back home I noticed he regurged a half digested pinkie mouse. I thought that this may be due to the stress of travel. So I waited a week and offered him another smaller pinkie which he readily took. I visually checked up on him for the next few days and on the fourth day I found another half digested regurg. I have one side of his cage set at around 85 F with a thermostat and heat pad and the other side stays around 70-68 F. The humidity on the cool side is about 40% and he always has a bowl of clean water. I am using aspen bedding and he has three hides spread out throughout the tank. Should I be concerned and do you have any advice for me?