I wouldn't worry about it. All of mine had stretches of days where they increased their frequency, and I know my supply was fine because they kept right on growing and growing. It is very normal for the pooping frequency to change after the first month, too, and for you to start feeling less full. The lack of fullness is a sign of your supply shifting from the immediate post-partum phase of being primarily hormonally driven, to it being primarily supply and demand driven. It's a normal transition. The lack of poop is often baby's digestion maturing a bit. Some babies past about six weeks go days or even weeks between poops, while continuing to grow and gain weight beautifully.
Your baby is entering the phase of the peak of infant fussiness too-- that peaks around six weeks, and then declines steadily afterward, for non-colicky babies. It's often a phase where they begin nursing extremely frequently, for a variety of reasons-- increased hunger and rapid growth are only one of those reasons. Another common reason is that baby sees the breast as a refuge in an overwhelming world. They start to wake up and become more aware of what's around them, and become easily overstimulated and overwhelmed, and returning to mama's breast frequently is often their way of finding safety and reducing the overwhelming stimulation.
And if your supply did briefly decline due to the illness, frequent nursing will cause it to rebound anyway.
So I would say that continuing to nurse on demand is the right thing to do, regardless of the cause. Don't rely on pumping output to help you evaluate your supply-- a pump is not an accurate measure of what baby gets, because the complex suckling action a baby's tongue and mouth use to extract milk cannot be imitated by even the best pumps. Also, the intricate hormonal interaction that occurs between mamas and real live babies can also not be reproduced with a pump. Many mamas with bountiful supplies can't pump even a half ounce.
Take me for example-- when I was nursing my twins, they were growing well and so obviously getting plenty of milk. But even four hours after a feed, I couldn't pump more than a quarter of an ounce at best.
