How long to wait to take a test

Elizabeth

How long after the first day of a missed period should I wait to take a test ? We have been trying off and on for a long time and I just do not want to be disappointed so I'm just wondering how long do y'all think I should wait before I take a test usually I think i may be preg and then the day that I take a test I start my period and I'm disappointed. Just wanting some second opinions