how long should i take for mat leave?

I'm based in the UK and get 6 months on around 90% of my salary (about £1,200 a month (I think about $1500?)), another 3 months on about 50% (about £700 pm) and another 3 unpaid. my fiance can support us financially and I'm saving like crazy right now, with about £1,000 to one side and expect to have about £2k saved by the time baby is born. Wary of doing my career damage by taking off longer than 6 months but want to be able to bond with my baby and dont like the idea of someone minding him when he's really tiny. post your experiences!