Im just going through this at the moment...
Last time round, i used sick leave for the 4 weeks prior to confinement dates, this time round my boss (different on but same job) has queried it.
Got a massive email from HR consultant today confirming that i can (i think) i have a meeting next week... But i spoke to the union as well and they told me that i cold use sick leave (as it is a medical condition that is preventing you from working) but i am not meant to 'plan' it... does that make sense. I do have to have a sick certificate though - but doesnt have to be from my OB, it can be from my GP...

Anyway i will come back later and post what was written in the email if you like.
What do you do for work?