When I reached my full retirement age (65.5) I started collecting spousal benefits (half of my DH's amount, he's still alive). I will switch to my own benefit amount this summer when I turn 70. These spousal benefits are only available to those born in 1953 and before, if I remember correctly. I just got in since I was born in 1953.
I seriously doubt you could go back and re-do things in your situation, but a call to your SS office sounds like something you should do. SS is complicated and there is a lot of misinformation or lack of information on boards like this.