crying baby

my baby girl is 3weeks old and last night/ early morning around 2am she started doing this thing where she cries every few minutes. we haven't given her any pacifiers since birth, but i gave her 1 this time. because she wanted me to just sit there and hold a bottle of perfectly good breast milk in her mouth for nearly 2hrs. she wasnt drinking anything and when i took it out she would cry like someone beat her ... she's been sleeping better since i gave her the pacifier but she still does the crying thing every so often and its now 7:30am. what in the hell is this? i dont wanna take her to the doc as it is flu season, but if its something medical I'll take her to get checked out....