Quoting Jays*Mama:" i dont think it can spoil them, but i think it can make them too clingy"
Actually, research shows that babies who are held often from birth and responded to within a reasonable amount of time (ie. not letting them get to the point of all out crying) are more independent than those who were left to cry it out or who had to learn to comfort themselves very early on.
OP, at 3 weeks old your baby is in the midst of what's referred to as the "fourth trimester". Basically, because of how our pelvises are shaped in order to allow us to walk upright, our babies are born more helpless than other primates because they have to be born earlier than they should be...otherwise, we'd never be able to birth them due to their size. So the first 3 months after birth are like a fourth trimester in which your baby is trying to orient herself to the outside world. She's been held, rocked, shushed, and been warm and secure inside you 24 hours a day, 7 days a week for the last 9 months. Even if you hold her for 18 hours a day, it's a HUGE cutback to what she is used to. As was mentioned, get yourself a Moby wrap (or make one...they're super easy and don't require sewing... Get 4 yards of t-shirt fabric, cut it in half lengthwise, and you have TWO Moby-style wraps). You still won't be able to get everything done, but your baby is only little once and she needs you more than she needs the house to be clean right now. Try to enlist a friend or family member for help at this time, and if baby's dad is in your life, have him give you a hand as well. If you wear her, respond to her cries, etc. you will find that she is more apt to be able to soothe herself when she's older, more apt to play alone while you get stuff done, more apt to explore, and less apt to be clingy.