love, relationship, and marriage are complicated, if you choose to go for someone that you love, what if the person doesn't love you the same way? moreover, love fades with time, commitment is what keeps it going...
As for your husband, why does he need the marriage certificate and why are you holding unto it, is there something important attached to having it in ones possession?
RE: REGRETS: WHY LOVE SHOULD BE FOUNDATION OF EVERY RELATIONSHIP.