So you mentioned that you have 4Mh. First block that you have counted shares is 403923 (2013-05-12 11:09:11) up to 404922 is about 15h.
Average difficulty for the blocks you have counted shares is 1.73. 1 hour with 4000 khash at 1.73 difficulty is 96.67 coins thus 1450 has been credited to your account.