taking a long time for wordpress to open

The last two or three days it has been taking an unusual amount of time(2-3 minutes) for my wordpress wp-admin to open and then when I “VISIT SITE” it takes a few minutes for it to open and sometimes get the page that lets you reload after timing out. Is there something wrong with wordpress or with my sites? I have 12 wordpress sites and they have all been experiencing this problem the last couple of days.