The one thing I will tell you that will probably be the hardest to achieve it not to worry about it too much. It can become an obsession and then I almost think the obsession with it holds people back.
Enjoy your new status as Mrs. Enjoy your step-son and see life through his eyes. It will bring you a joy that is refreshing.
As for nosy people asking WHEN, tell them you are to newly married to have extra people in the bedroom and they'll know when you start wearing a t-shirt that says "I'm knocked up"! Or if that's too blunt for you, turn it around on them and ask "why did you want to know" with a sweet smile. Just find some way to let them know they are being TOO nosy right now. Don't let outside influences put more stress on you.
Good luck. It will happen for you when it is meant to, that I truly believe.
CONGRATULATIONS by the way,
C. B