Maternity leave

So my bosses are wanting to know when and for how long I take maternity leave for. I thought there was a set about of time people got but apparently I tell them how long I want. I’m the kind of person who knows money is important but my baby is a baby once and I don’t want to miss out on that to go back to work 9-5 right away. It will be unpaid but that won’t be a problem for us. But at the same time this job is relatively new and I don’t want to “push it” if you know what I mean.

So my question is; mums who work full time, how long did you take off? Was it enough? Did you want more? Was it too long? Please tell me I don’t know what to do!