Having a debate with my DH about this - he thinks I'm BU, I think I'm NBU.
I'm 32 weeks pregnant with my first child. Don't think I fully appreciated what being pregnant would be like - there seems to be a conspiracy out there to ensure that childless women don't find out how debilitating pregnancy can be until they're upduffed themselves! Morning All-day sickness till 22 weeks followed by all-day heartburn, sciatica, bla bla. All of that.
I managed to deal with that stuff more or less ok. No time off work.
However, I've suffered from severe clinical depression for the last 10 years. It's usually very well managed - low dose antidepressant in Summer, medium to high dose in Winter. I'm off meds due to pregnancy. GP, midwife etc were fully warned at my booking-in appointment in July that I would require additional support during pregnancy, especially November - February as that's when I normally need a decent dose of chemicals.
To cut a long story short, both midwife and GP have really missed the boat. Kept telling me they were referring me to counselling, to peri-natal MH services for extra support, but none of it has actually materialised. I found out 2 weeks ago that the referrals I was promised weren't even done. GP has now done an urgent referral and I've been signed off sick. Taking antidepressants isn't a realistic option as the one (!) medication that doesn't give me killer side effects would have killer side effects on my baby. Possibly literally. 
So I'm off sick. I have a pretty 'high-powered' job, managing a significant team of people, and I actually love my job when I'm not too exhausted to even open my eyes in the morning or burst into tears every 30 seconds.
GP and DH are both saying I should just stay off sick till the baby arrives now. But I very, very strongly feel that I'm letting people down. My maternity cover hasn't started the job yet, handover materials have not been done, my boss is useless (He reacted to me being off by 'parking' all my work so I can deal with it when I'm back. Even the super urgent stuff. So if I go back, I go back to a crazy pile of overdue work.), my team is lost... I just feel completely and utterly useless, like I'm letting the team down. My head is racing with all the unfinished work and I worry about it endlessly.
In 10 years of dealing with this depression crap, I've never been signed off because of it unless you count an essay extension of 3 days in my final year at uni.
AIBU to want to go back to work next week, even if I'm not feeling myself?