Do you have to be ovulating to get pregnant ?

I am trying to get pregnant but I want to know do you have to be ovulating to get pregnant ?or can you get pregnant before you start your period? Cause I want another baby so this would be my second child but I want to know is it harder to get pregnant the second time cause it seem like we are having trouble to get pregnant second time around lol. But please give me advice to know what can we do to help me get pregnant faster or differnt ways to try things... I would appreciate it:)