At a loss

Monday I was startled to find out I was pregnant. I took a test at the end of October and got a negative. I was dissapointed, but not sad.
Two weeks later I was feeling pretty cruddy for several days. And not the I-have-the-flu type cruddy, but the I-remember-this-from-when-I-was-pregnant-with-Ben type cruddy. So I retested and got my positive test! Jon and I were thrilled.
I admit, although we were trying for this pregnancy, I was scared as well. I had a few moments where I questioned if we had done the right thing. In the bottom of my heart I know we are, but I always have a moment of panic when I get that positive test. I don't know why, but I do.
Then Wednesday came. And things just felt off. Aside from the all day queasiness I have been dealing with I didn't feel right. Around noon I started cramping pretty bad. And then I started bleeding.
I was scared. I called Jon home from work. I called the doctor who sent me in for blood work (which will be repeated Friday and Monday). But now 24 hours later, the bleeding continues and it is clear. I miscarried this baby.
I don't know how to deal with my feelings. I am unbearably sad for this baby that I knew about for 2 days. Even with my moment of panic (which I feel so guilty for now) I WANTED this baby. And now, just like that, it is gone. I don't know how to move forward from this. How do I grieve for something so small?
I am so incredibly lucky for the three healthy children I have, which is more than many. But they don't understand why mommy and daddy are quiet and sad. They worry, especially Madeline who picks up on these things. How do I grieve without scaring or worrying her?
We didn't tell anyone about this baby. We only learned Monday and were planning on waiting until Christmas. How do I tell those who matter most that I was pregnant and no longer am? Do I tell them? But at the same time how do I not tell those who I depend on most? As of now I have told only one person who is being amazingly supportive. (And those I am close to in real life don't read this blog so I can pour my heart out here somewhat anonymously.) Jon and I are suporting each other through this, but I question if we should reach out to others or simply help each other. No one else can feel the pain we feel for this baby, but they will offer support and a shoulder to cry on.
How do I take the chance on another pregnancy? How can I even think about that now?
I am struggling with my feelings. I want to grieve in the right way and be able to move on with life, not forgetting, just moving past. But how long do I allow myself? Do I give myself a time limit on this?
And how do I deal with the holidays next week? I have days and days of planned activities. I don't want to skip them but at the same time right now the last thing I want to do is put on a happy face for others. I simply want to curl up in bed and close my eyes.
If only I hadn't taken that test. I wouldn't have known. I don't know if that would be better to never know that this life was there. In some ways it would have, the pain would not be there. I would be enjoying the holidays. But at the same time I wouldn't have known about this life. And the idea of that makes me sad as well.
I guess for right now all I can do is take it one day at a time. I just don't know how to do that exactly....