Take a leave of absence from class. Tell me how to write.

I ate my stomach yesterday. I got up with a stomachache in the morning, went to the toilet several times, and didn't have the strength to walk, so I lay down and slept again.

As long as you say so naturally, the teacher will believe and forgive you. After all, he has so many students that it is difficult to guarantee that no one has any minor problems.

The key is to speak naturally.

Pour!

Then say you have dysmenorrhea or are pregnant!