I want to finish work earlier than agreed....what should I do?

[Alexo]

I am working in a school covering maternity leave - I found out I was pregnant 2 weeks after I started the job.
Early on I agreed to work up to 38 weeks - this also coincides with the end of term.
I?m now regretting this decision as I want to finish at 36 weeks instead.
My dilemma is how to get round this, I could speak to my manager about it, but she would not be happy at all and it could make things quite awkward for me - she has always said to me 'now your not going to leave early are you' or 'don?t go getting pre-eclampsia and finishing early' or 'you hold onto that baby now' etc etc. She says it in a joking way but I know she is serious. This is the main reason that I feel like I should stick to the original agreement as I don?t want to leave people in the lurch. But at the end of the day my job is stressful and all I want to do is finish and nest!
I wont be coming back to this job after my pregnancy as the other lady is coming back so it wont affect my maternity pay (I?m only getting SMP anyhow)
I juts don?t know what is the best way to play it!
Help!

How pregnant are you at the moment?

I think you have to give 28 days notice.

I woulnd't worry about sticking to what you've agreed to and do what is right for you. It might be different if you were going back, but you're not so they will just have to cope for 2 weeks.

give 28 days notice, and take it. You and baby are more important than two weeks of cover. If you give them as much notice as possible, they can arrange cover, that is much better than going sick with the worry of it all and really leaving them in the lurch.