In Chapter. 11

Dimmesdale still believes that he has done wrong, even when his feelings have not abated, and we sense that he cannot take public claim for Pearl's birth not only because he is afraid of the town's reaction, but also because he believes he can somehow atone for the sin enough to allow him to stay silent. His assertions of guilt are ironic because, in chapter 11, he still cannot completely confess his sins: he still hides behind Hester and Pearl.