You're doing the right thing by calling rather than texting. If she doesn't pick up, I usually leave a short message teasing her about not being able to get to the phone for whatever reason and to text me later so I can call her back - the last thing I wanna do is call her again when she's in the shower or something and she falls and breaks her ass trying to get to the phone in time.
Stuff like that will get a laugh out of her, and show her that you're not too serious. It also gives her peace of mind that you're not gonna keep calling and texting her, so she has some space to breathe.