Well done on breastfeeding for three weeks! That is wonderful, really a lovely achievement. It can also feel as though there is nothing BUT feeding in the first few weeks; and that your breast is constantly on display! Babies love to be on the boob, and during that time they can move from active sucking to just nibbling a bit and then back to having a wonderful feed.
There are problems associated with using a dummy, though.
http://www.kellymom.com/bf/start/concerns/pacifier.html - it's especially a problem in the early weeks, and perhaps your lovely little man is hitting the three week growth spurt?
Maybe this would help encourage you during this draining period?
http://www.lalecheleague.org.nz/temp...doing_this.pdf
Best wishes
Melanie