No, that is not your social security number. This is your Medicare number. You are currently claiming wife's benefits on your husband's record. (That little symbol "B" is Social Security's code for wife's benefits.) So as long as you are claiming wife's benefits, your husband's number with a B behind it is your Medicare number.
Once you reach age 70 and switch to your own Social Security, you will then be claiming your own retirement benefits, so you will get a new Medicare card that will have your own Social Security number with an A after it. (That A is Social Security's code for retirement benefits.)
Look at your social security card to find your social security number.
Related information:
Your Medicare Number May Not Be Your Social Security Number https://www.creators.com/read/your-social-security/11/13/your-medicare-number-may-not-be-your-social...
