To baby or not to baby... is this a question?

I personally have never been pregnant. I deeply want to have children in this lifetime and all that jazz but I still have 4 years of university ahead so not now. As a doula, I've noticed that this is a sticky point for some people (mothers and other doulas alike). Sometimes I read in books, magazines and articles that doulas are women experienced in childbirth and are themselves mothers...there is often a huge emphasis on a doula having given birth herself. This is very important to many women who want to know that they are being supported by a woman who knows and can attest to the feelings of labour and childbirth. I have always been upfront with the fact that I have not. Some women are happy to know in advance and decline my services. Others say 'thats great, it means you can come see me in labour on the spur of the moment and won't compare my birth to your own and super-impose your expectations on me.' I don't doubt my capacity as a doula because of these personal preferences. But I do wonder about the (new) age old question: can we have it all~at once~? For career women, when is it appropriate to have children? Is it possible for me to continue my work as a doula and become pregnant, have a baby and carry on with my professional life? Our country still owes women so much in the way of support for surviving while having a baby. And on that note, since I've chosen to study midwifery, when then, will it be a good time for me to have a child? Will I again be faced with decline on account that I have not myself given birth? And what about midwives who are infertile or chose to adopt? What then do they represent?
A dear friend and midwife that I know asked me "so how do you really feel about this?' when I first told her of my acceptance into the programme de sage femme. I sighed and said "well I'm just thrilled that I can now have my children before my mid 30!" Her answer: "You're in now. You can have them anytime. It will never be a perfect or easy time to have them."
A pregnant midwifery student, a mother of a young child midwifery student? Is this really possible? How and why are women expected to do it all at once?!!