right, cost it out then, what you get in each month - childcare where I am works out at £1k a month for 8am - 6pm, would you be able to work hours that would fit in with that? Most nurseries and childminders arent available for more than 30 minutes either side of that, and you will pay more for that.
Weekend work, is very hard to find formal childcare for - and most teens would not be happy being left for a long time with a small child. Can you move to working daytime only?
you might not have been sick as an adult yet, but you do need to factor in that childbirth is rather damaging to a body, it's a hell of a thing to go through - plus that nurseries are a hot bed of illness - most children spend the first few months getting a selection of colds and bugs, often passing on to parents...
you own a flat outright, so that's helpful, no housing costs to start with,you could easily share a room with your DC for the first couple of years then you sleep in the living room, make the bedroom their room for another 10 years or so. Would moving be an option later on? Either renting out your flat and renting somehting larger? This could be saved for now/over the next 10 years.
I would say delay a year, save as much as you can and see if you can retrain/gain additional qualifications for a better paid job, and possibly see if you can meet someone to have a baby with.
Do be very very careful about planning on current benefit levels, Labour seem to have given up on the next election already so we're looking at 10 years of the present government who are committed to reducing the welfare state. Anything you get has to be seen as a bonus, you need to be able cope by yourself.