Pumping- How many times a day??

My girl is 3 months (on the 7th) I’m trying to pump every 2 and 1/2 hours to keep up my supply but it’s exhausting! How often do you mommas pump if you do?

UPDATE: I’m getting around 3 oz (right breast) and 2oz (left breast) from my 20 minute sessions. After 10 minutes I physically have to massage or press my breast for anything to come out! Totally takes out the “hands free” from my pumping. I’m trying to aim to pump (at longest) every 3 hours daily. I seriously suck at math. How many oz am I making a day? I’m going to “keep track” of my oz today to see! Any advice or comments are appreciated. You guys are great ❣️xxx