Hi mama! Three weeks is a bit on the longer side, usually it falls off between 1-2 weeks, so I'd really suggest having your pedia check it out just to be safe, especially if may discharge or redness around it. A few of us had the same concern kaya dala lang namin sa check-up, and good thing nag-check kasi some babies need a little extra care or cleaning. Better peace of mind, di ba?