haha, no
ただいま LITERALLY means "just now"
it is short of ただいま帰りました
where 帰る literally means "go back" or "return"
which can also means "go home", but it is not the literal meaning, since the complete "go home" needs 家に for that
which is why ただいま can also mean "I'm home"
but it is not the literal...