Can anyone relate to this?

Can anyone relate to this? Or offer me some words of wisdom? My husband and I are 29 and 28 years old. We got married in July last year.. It had always been our plan to wait a little while before we tried to have a baby. We were thinking we would start trying in the spring of this year. My husband has a good job, however I have always been dissatisfied in my career. I recently was accepted to grad school and will be starting in June for 14 months. I'm currently a school secretary but recently got accepted to do my masters of education to be a teacher. This will dramatically increase our income as well as my job satisfaction. However now that I am returning to school we will have to put TTC on hold. This career change will also mean I have a long road ahead of me until I'm able to obtain a permanent position as supply teaching is also a seniority-game. I feel so disappointed that we have to put TTC off for at least another year. I always imagined myself becoming a first-time mother in my 20s. Now I won't even be able to consider TTC until after I turn 30, which will result in my baby being born at 31 IF we don't have any complications when we DO finally get to try. My younger sister is already finished having children and we are a year apart and I feel disappointed that our kids won't grow up even close in age at all (her kids are already 5 and 2). Has anyone experienced something like this? I wish I figured out I wanted to change careers a few years ago.... Maybe I just need to vent....

Edit - thanks so much for the kind words everyone, I needed to hear it! Some suggested that I don't put off having children but I'm kind of backed into the corner at the moment and have to at least wait until I would be having baby after I graduate. I think that is my tentative plan - to try to get pregnant in one year in the spring time so that I can finish school and then focus on getting on the supply list while enjoying motherhood.