I had my tour just recently at 37 weeks, Im 39wks now, only because I didnt want to do it early and get excited and have to wait sooo long for the baby after...lol...makes me feel like im almost there!!!
I toured the hospital at only 15 weeks this time. I was considering a great doctor that I was really impressed with but, she delivers at a hospital I have never used before. So, I went to see it. It helped me feel more comfortable with my choice of doctor.
I'm not doing one this pregnancy because we are delivering at the same hospital but with my first I did it around 6 months and I was probably the earliest one their. Some ladies in 9 months. I've also known moms who went when they were like 3 months along. There is no set time just what ever works for you.
I do think its a good to do the tour than when your in the midst of the craziness of labor and getting to the hospital you know exactly where to park where to go and what is going to happen. It allows you to relax a little.
Also some hospitals have preregistration you can do at the time of the tour or online. That is also nice as its one last thing to worry about when in labor.
Ask your Dr.its always best for you and ur birthing partner to know where you are going