Wanting to be supportive but unable to understand.

I have 2 friends that both got pregnant when they and their BF's had no jobs and we're living with their parents and just barely a year out of high school. That they were actually actively trying for while in that situation. Now they've been complaining a lot about not having money and not being able to go out and do things and I'm finding it hard to empathize. My husband and I want a baby right now but know we couldn't afford one and were not even in that situation.
We are waiting until we know we have enough money and planning ahead so that I can stay at home (because that's what I want) and were being responsible with not having a baby now so that we can truest enjoy our baby even if we will need to be very frugal.
...
Both of these girls are lovely, but with all of their "planning" for a baby they didn't seem to realize that you need to have a job to pay for THEMSELVES let alone a baby and that babies take a lot of time. I try my best to be kind, but I sort of want to shake them and shout "what did you think you were getting yourselves into when TTC?!"
...
Am I a terrible person for feeling this way? I know that they're unloading on me as a friend; thus, I wouldn't say anything and just support them in their rough time... But I find it hard to believe nothing like this was ever a concern when they were trying for a baby while being jobless and essentially homeless. How do I cope with these terrible feelings? I'm not usually one to judge and I don't know how to handle all these harsh opinions I have all of a sudden!