hi claudia, i am so excited for you and your little one! DH, too!
here is how to post a picture.
1) open a new post window and scroll down to image services Photobucket.com. click on Photobucket.com
2) create an account with login and password
3) go to browse and select the photo off your computer, then click "upload"
4) once the picture is in your account, you select the text in the url window that says "http://....." and paste it in your message.
this SHOULD work and i have followed these steps and pasted a picture of my favorite sesame street character.