may be you have not changed base secure url in mysql database.
try this :-
Method 1: change Magento base URLs in Magento administrator panel
Log into your Magento admininstrator panel.
On the top menu bar, click System > Configuration.
On the left menu, click Web.
Open the Unsecure and Secure dropdowns, locate the base URL line, and replace this with the new URL.
Clear the Magento cache and your browser's cache. The site should load properly now.
Method 2: Change Magento base URLs with PHPMyAdmin
> MySQL > PhpMyAdmin.
You will be brought to the main menu for phpMyAdmin. On the left side of the screen, locate and click the name of the Magento database corresponding to URL you want to change.
You will see a list of all the tables in the database in alphabetical order.
Search for the
core_config_data table and click Browse.
Expand the viewing area of phpmyadmin. At the top and bottom in the main panel, locate the grey box and change the number of rows to a larger number, such as 100.
Locate the rows
web/secure/base_url and click Edit next to the corresponding lines. Change the base URL to the intended string, and click OK.
Flush the Magento cache, and the site should load with the set base URLs properly now.
Method 3: Change Magento base URLs with the command line
Attention: Due to the possibility of irreparable damage, do not attempt to change the base URLs unless you are an experienced technician.
s, execute the following commands:
update core_config_data set value = 'http://domainname/' where path = 'web/unsecure/base_url';
update core_config_data set value = 'http://domainname/' where path = 'web/secure/base_url';