Jul 31 - 10 months aga I was in Nicaragua

I think the above title, ("10 months aga I was in Nicaragua"), would be

Hace diez meses estuve en Nicaragua. yes/no/maybe ??

If I trim the above title sentence to ... "I was in Nicaragua" does that toss the sentence into the Imperfect, ( Estaba en Nicaragua ), because no time reference is specified?

Thank you