Missing her

I would like to know if im being unreasonable or petty?
my girlfriend usually calls me at least 5 times a day or more , yesterday she didnt call me because she had things to do with her family , 28 hours had passed. she called me and told me she missed me so much but i was not very receptive on the phone due to this long time between calling? she wasnt very happy that i was disapointed . how do i deal with this missing issue of not hearing from her. am i wrong to think like this or is she wrong not to call?