In my opinion, this is bad advice if you wish to fully feel your submission and enjoy your master's dominance over you.
Yes, you have the ultimate right to end a relationship or the D/s context of your relationship (but so does your partner.) Yes, it is unrealistic to believe there are no limits between you, but do not presume you have control or are in charge. You make an agreement to release control to your dominant and that's what you want to experience. You do so to experience the journey in his (or her) care.
If you think of yourself as "in reality being in charge" (sic) then you will never feel your submission.
Have these conversations about what went right and what made you uncomfortable between sessions. Unless you are in distress mentally or physically, don't do so during the session. This will improve your ability to submit and his to dominate.You tell them what is ok to do to you and what isn't. What you're willing to try and not try. If they are good Masters they will respect that but at the same time they will push you too. Don't forget you are a slave of your own free will and can back out anytime you want. Even with a contract because even legally you can't sign your rights away. If the situation is going too fast tell them to slow down, if you're just in shock due to the suddeness of it but are secretly pleased just go with the flow. Remember you may be new at being a sub and need to be trained but it sounds like your Husband is new to being a Dom and it is a training time for him too. Dom's need just as much training as subs in order to do their job correctly. He may just think this is what he's supposed to do. It's a team effort, especialy if you're both new. hoped i helped.
I'm not saying what concubine suggests is wrong per se, and it may work well for her and her partner, but most people who are new to D/s aren't going to achieve any emotional context by trying to be both "in charge" and submissive... You may find physical pleasure in the bottom role but may well miss out on the emotional context of a D/s relationship.