Throwing up

I went to the pet store and was sold a mouse when I got home it was obvious that the mouse might be to fat for my snake to eat. He tried anyway and swallowed it then through it up. There was also some blood which I couldn't figure out if it was coming from my snake or the mouse. Is there away his mouth or throat can tear? And I think the mouse might have been pregnant because it had like 6 nipples.

Well the way to adequately feed your snake is by estimating the widest part of the snakes girth at the belly region and select an appropriate sized prey. One that would leave a small bulge and that's all. Depending g on the age and weight of the snake sometimes there is a calculation of 10 -15 % of the snakes weight as being an appropriate sized meal. Never over feed your snake or give it oversized prey bc it can certainly lead to a regurgitation. Which is what this sounds like. What type of enclosure is he in and what are the temps inside? Hot spot, ambient and cool side temps and humidity? Inadequate heat and overheating can also lead to regurgitation. You will have to give the snake time to recover from this episode by not offering any meals for the next week to 10 days.

Do you mean got it completely down and then regurged the next day or tried to eat and only got about half way down and stopped trying?

Yea he got the whole mouse including the tail down then he started coughing and choking and it came back up

Wait 3 weeks for the snake to heal and offer a half-sized feeder next time.