I'm not going to call my mom right away
Why don't you want to call your mom?
Because I don't want to give her any reason to worry about me.
You would be worrying her more by not calling right away. If they are expecting you to call then you should do it.
She does a lot for me and I don't want to give her more trouble.
She's your mom so it's natural that she worries about you. Not calling her right away will make her anxious so if you really care for her you should call her right away and tell you're alright.