How to prepare

When it comes to my cancer, I know that God and I have it beat. But still I can't help but be a little pessimistic sometimes. My doctor said that this cancer will eventually kill me. Whether it's a year from now, or 50.
God forbid it should be sooner, rather than later. The question comes up, how do I prepare my son for the day mommy might not be here anymore?
It's such a difficult question to not only ask but answer as well.
My heart breaks at the thought of not being around to see my son grow up. Or being able to grow old with my husband.
I guess the only thing I can do is keep trusting God that his plans are to prosper me and not harm me. I have to keep believing that with God, I've got this beat! Not just for a couple years, but forever.

CT results

Yesterday I had a CT scan of my lungs. Last time it showed a bloop of something in the lower section. The ct yesterday showed no change in size or shape so the Dr thinks it's fluid. Thank God!
On another note, I'm sure I've mentioned before that my hubby and I would like to adopt kids. So, we started looking into it about a week ago.
Today Keith asked the doctor for his opinion. The Dr's reply was not one I wanted to hear... "wait a year, until you've been on the chemo pill for 2 years. If things haven't changed for the worse then look into adoption."
That means my son will be 3, going on 4, before we can do anything. :( on the upside he'll be potty trained by then, so I'll only have one person to diaper. :)
It's difficult to be patient but, God promises that all things work for good. And He knows the plans he has for us. That means I need to be patient and trust in the Lord.