I agree with Rockrose. Stop telling her anything at all. And If your husband tells her after you make it crystal clear that it's none of her business then put him out on the curb with your next garbage day.
You need to stop sharing anything with her that you don't want broadcast. She has no filter at all.
Next time you have a doctor appointment, say your shoulder was bugging you.
Go on her Facebook and say, "Cut it out, Myrtle, I don't have a yeast infection."
Talk to your husband about his mother's over sharing. Explain to him how it makes you feel. It is his mother and HE needs to understand that he needs to stop over-sharing with her because she over-shares with the world which embarrasses you. My husband and I have a rule regarding families--it is his job to deal with his family and my job to deal with my family. He needs to understand that while she is and was his mother, You are now his wife. In order to have a happy marriage, in-laws need boundaries. The two of you need to discuss those boundaries together and agree on those boundaries. Then he needs to enforce the boundaries for his family members and you need to enforce the boundaries for your family members. Thus, your husband needs to have a talk with his mother about how her over-sharing has embarrassed the both of you (not just you because this makes you the bad guy in her eyes while using the language of both of you means he is disappointed with her telling the world as well) thus from this point forward she will no longer be allowed to know any information regarding your marriage, your health, nor the possibility of whether or not you and he will have children or not so she should stop asking. This will upset her as she seems to want to be overly involved but he needs to stand strong in that she over-shared information that she should not have shared. Thus in the future when she wants to know something that you dont want the world to know, you should be able to look at her and tell her that when you are ready for the world to know then she will be the first to know, but that right now this matter is between you and your husband only. If your husband refuses to support your wanting some boundaries set and/or does not understand why you feel this was over-sharing--then perhaps you and he need therapy rather than a doctor to help you have children.
Sorry about the difficulties with Mom in law. All you can do is to no longer let her know your business. Every one that she has told, has their own similar problems to deal with and they all will pray for you. Try not to let it embarrass you. Although she should have respected your privacy, these issues are real life problems for all of us and nobody will give it a second thought, but to feel sorry for you that your mother in law is such a ditz. Good luck.
I would pray that God will protect you from that publicity...He can do anything, like cause people to forget it, or cause them to understand that she never should have said that!!!
Let vengeance be the Lords, and try to let it go, and I would never tell her anything personnal!!! So sorry for you, but people do forget things and they know she was so wrong to do that!