Slow server with wordpress

[backint2]

Hi, I have Wordpress installed and from yesterday i have noticed my page was really slow, Im not sure where the problem comes from but I made different speed tests and seems like the server takes more time than usual to act. These are the speed tests i take:
http://tools.pingdom.com/fpt/
https://developers.google.com/speed/pagespeed/insights/

Can someone help me with this?
Thanks in advance