How do I convince my mom....?

Today I stayed out of school, Because of girl things..Mama was pretty mad because i hadn't told her the night before, But she just let me skip today, Well, Thursday is our last day of school and we're dismissed at 12:30. I want to stay out tomorrow, I have EOG retests, but I ped the grade (I also had them today) I really just want to relax at home tomorrow and Thursday after all the hard work i've done this year! and i don't want to play sick, I just need a mature way to convince my mom on letting me skip tomorrow..Any suggestions?