Working Mamas - How do you handle it?

Maya
Hi,
I am 7 wks 3 days and am having full blown, day-long nausea, exhaustion and the ever lasting headache. I work a pretty typical 8-5, M-F schedule (with two night classes thrown in) and am having a tough time handling even going in some days. I haven't called out sick yet but I feel like that will happen inevitably with the way I am feeling and the length of time I have left in the first trimester. 
I know I'm not alone here so my question is how are you other moms-to-be handling this? Do you give your boss an early heads up to give him/her some perspective? Do you just suck it up? This is every day all day for me and I'm not sure what to do.
Any insights would be welcome!