~That it will f*** up your mind and leave you unable to think about anything but the last time you felt baby move. Seriously. Work, hobbies, television...you will not comprehend a thing. You will read the same paragraph a thousand times...ask people to repeat things...find yourself watching a television program and realize you have no idea what is happening (thank heavens for DVRs). Take "pregnancy brain" and multiply it by a million. It's awful. And if you're a Type A, like me, it will drive you mad that you have spent an entire day looking at your blank computer screen and have basically accomplished nothing.
~That you will have deep dark irrational fears about losing everyone you love and being left completely alone. That you will actually contemplate how you will continue your life without those people you love. That you will make an effort to say "I love you" because you don't ever want to have the regret of not having said it.
~That with every twinge, sore throat, and sniffle, you will sense impending doom. That you will have to remind yourself that most babies live and sometimes a cold is just a cold. That it is really unnecessary to change clothes three times a day and/or wash your hands and body a hundred times each day.
~That you will be more tired than you have ever been in your life and a good night's sleep without nightmares is a GOOD thing...not some harbinger of bad news. In fact, you may find yourself yelling at the top of your lungs at those signs you used to take such comfort in. Make sure, when the tears come, that you are not driving a car.
~That other people have moved on. That while it is a very real and present danger to you, your losses are things of the past that have no bearing on today for almost everyone you know. It is an immediate thought for you every single second of the day (except when you distract yourself enough to push it down). But that other people will often need to be reminded and it can take a toll on your patience and your understanding.
~That there is happiness to be found in being pregnant, but it probably won't be the same as you had before...and you have to accept that.