No routine yet

Does anyone else baby not have a routine yet? I really don’t understand...my baby is so random with her feedings...one time she might be satisfied with 3 ounces every 2 hours the next feeding 2 hours later she eats 4...then will go 3 1/2 before she’s hungry again and only drinks 3 etc...this is driving me crazy! Or she will go 2 hours and only drink 2 ounces... Why isn’t she consistent yet...shouldn’t she be eating a certain amount within a certain amount of time (example: 3 ozs every 3-4 hours) once I think she has a pattern down it changes.