I started social security benefits based on my late husband's work record in January 2011 when I was 61. I am now 67, and plan to switch to my own work record in January 2018. Was I supposed to have taken some action when I turned 66? I have seen statements on the web that one has to "suspend social security" in order to earn delayed retirement credits. I had thought that I would earn DRCs automatically just by the passage of time. I am going through hardship to wait this long, and am so worried that something will go wrong. I hope that I have been earning DRCs. Thanks for your advice.
No, you don't need to do anything to accrue delayed retirement credits (DRC) on your own record. DRCs begin accruing toward your retirement benefits when you reach full retirement age, as long as you are insured for benefits on your own record, and you defer taking them. You aren't required to file and suspend to receive DRCs.
If you weren't receiving widow's benefits, it would not have mattered whether you filed and suspended at age 66, or simply didn't file. Since you are receiving widow's benefits, however, it would have been a big mistake for you to have filed and suspended on your own account. Assuming that your own benefit rate is higher than your widow's benefit rate, filing and suspending would have caused your widow's benefits to stop, and would have made no difference in the DRCs that you receive on your own account.
So, it certainly sounds like you have done everything right so far. The only thing that you might want to consider doing differently is waiting until age 70 to switch to your own record. You may want to consider running the maximization software available on this website for a full analysis of your filing options.