Pretty much constantly. I told our MW that I didn't know how often DS fed because I didn't know what counted as a 'feed'. I think I had vague expectations of 'twenty minutes on', with an hour between feeds, etc. It just wasn't that clear cut in reality! more like '5 mins on, 10 mins nap, 7 mins on, 20 mins on/off/fuss/cry/burp - ooh, an hour nap! then 15 mins feed'....
So it was either one long feed all day, with small breaks, or a hundred feeds. Depends how you define it, IYSWIM.
I found all the 'newborns feed 9-12 times in 24 hours' info very misleading. It's too neat a description. I kept expecting breaks which never came, and this got me down. I also think the expectation that feeds will be very 'defined' come from a bottle feeding culture. Not a criticism of formula feeders, I'm just pointing out the mechanics of bottle feeding make it a more defined act. The feed only starts when the bottle is ready - formula has to be thrown away after an hour, etc etc.
I should point out that DS was and is v healthy,and thriving. He was obviously doing exactly the right thing for him. I found it very demanding. It has got a lot easier at 13 weeks, btw... just like everyone said it would...