Hi Lotta,
I'm in a similar position. My DS was in childcare mornings (I'd pick him up at 1pm) but due to morning sickness (I couldn't really walk without barfing) and my childminder being a 20 minute walk, i had to lengthen his hours to 3pm in the afternoon.
When i start maternity, I was considering him doing mornings again, but given that would mean me having to be there at a set time each day (and knowing new babies aren't all that keen on timetables).
I'm going to arrange for him to do two full days (either until 3pm or 4pm, will see how it goes). The other mornings he has playgroup, so I will get a couple of hours each day of quality time with new baby.
I figured if he did 2 full days, meant I could have more relaxing days with the baby, and if I was out visiting friends or out for lunch, it would give me more time.
I get childcare vouchers, and my amount of 220 a month should cover his place for 2 days a week, so hoping we will be able to continue his childcare without it costing us anything while on stat mat pay and unpaid mat leave.