hungry baby milk??

My baby is 5 weeks old she was 3 weeks early I had GD.. She weighed 8lbs 3oz she is now weighing around 10/11lbs.. She is taking 5oz of milk every 3 hours she spits little bits here and there up, but of a night she can take a fed and straight after want another bottle... Should I put her on hungry baby milk? She's currently on aptamil.. Any advice would be great thanks