I am 64 years old. I was married for 13 years when my husband died. I was 32 and pregnant. I collected widow's benefit until I remarried and then it went to my kids until they were 18. I remarried a couple of times but divorced my last husband in 2009. I contacted the SS office and can get SS from my first husband. My question is should it be retroactive back to when I was 62 and can I continue to get his and let mine grow until I am 70 or beyond if his is more than mine would be?
No, if you file for reduced benefits before your full retirement age (FRA), you can't be paid for any months prior to your month of filing. This applies to both retirement and widows benefits.
You could, however, start drawing reduced widow's benefits now and then potentially switch to your own record at age 70. Or, it may be better for you to file for reduced retirement benefits now and then file for unreduced widows benefits at FRA. But, the Social Security earnings test could limit how much you could draw prior to FRA if you are still working (https://www.ssa.gov/planners/retire/whileworking2.html).
The maximization software available on this website can help you determine which filing strategy is best in your case, as well as when you should apply for each type of benefit.