she is not your girlfriend,
you guys are just "dating" she has already labeled the relationship.
don't worry about that, NEVER talk about where you stand in the relationship, let her be the one who will call you her boyfriend, first.
break that rule and you will be in trouble.
anyway, just follow the same DJ rules that apply to any other girl you are just beggining to date or getting to know... text/ call every now and then, then back off and let her reply and initiate texts so that she can miss you...
I personally call them, if they don't answer I wait for a reply and don't call back, or I wait for them to call me at least 2 or three times before I make the phone call.
then get on with your life doing your own stuff until she calls you back, always have a life of your own, don't stay around at home waiting for that phone to ring, that's a huge mistake.
remember rule number 2:
ALWAYS GIVE HER THE GIFT OF MISSING YOU.
it is a gift for women
guaranteed.