An i worrying my self sick for nothing

My husband has been in the army since 2008 and we have been married 3 years now I have 2 kids by another guy who died in a car accident. I was on birth control for the last 3 years and I haven't been on any in about 7 months now I am worried we may not have a baby because it hasn't happened already does tricare cover him being tested to see if he's even fertile. I know I can have kids because I already have two. I have baby fever some kinda bad and really want us to have another baby but so far nothing has happened. He's also the last male in his family so if he doesn't have a son he has Noone to carry on his family name and we really want a baby boy