Currently I have only one child who is 18 mo old. I too had pregnancy "scares" (when I get overly tired I get all the early symptoms of pregnancy, esp moring sickness). :-) But since he still is not sleeping through the night, I am glad I don't have a second baby on the way yet. However, I know someone whose babies are 17 mo apart and they are very happy.
My doctor did say 2 years from birth to birth gives the woman's body enough time to heal, and the older child is a little more independent. I read in a magazine a study that said at least 18 mo before getting pregnant again is ideal. I have heard others say that you want your 1st to be a little older, because it is hard to carry 2 up the stairs. So, if you have a baby before you inteneded, it will work out, it always does. But you might consider waiting a bit before trying.
State Certified Early Childhood Special Education Teacher
New Mom as of March 2009!