Did I just ditch a class....

So I got to go home for lunch today because my class has french after lunch. So I come back to school and at the bus stop are kids from my class. I ask them where are you going dont we have computer class? And they try to explain to me in german but I was a little lost but basically they said we do to have computer today that we are doing a project and dont have to come. (I guessed we had spoken together about 15min)
Then im all bummed because I could have stayed at home for another hour before my last class of the day.
So I go into the school and go to my class table and I notice that all the kids stuff is there.,,, I look around for them and  THEY ARE IN COMPUTER CLASS! So im late and I think theres less tham half the class left so I go and sit at the table for them to finish. After 15 minutes I check the time.....if I had entered the class when I first got there I would have only been 3 minutes late. Sigh. So im sitting at the table and my homeroom teacher (in charge of absences) is walking towards me and I freak out and continue drawing.... she didnt reconise me and kept walking.
The whole time I feel bad because there was no reason for me to miss the class besides miss understandings. When my class comes out I ask then if the teacher noticed I wasnt there and they said "there was no teacher today, you didnt have to come"
Well ALRIGHTY THEN