Forgetfulness is no longer funny

I have no idea what is wrong with me.
I forget the simplest things, I can't focus, especially at work. I have been doing so well up until last month and then it felt like I fell face first into the dust.
Basically I crashed and burned. Sadly, I am starting to question my ability to do this job and let me tell you its a no brainer job. The stupidest thing would be to give it up an look for something else, yet I can't seem to motivate myself to do my daily work. It isn't hard, just tedious and long. I started to write myself little reminders of the smallest things so i don't forget.

I can't believe I forgot the two most important reports, and my boss is not happy with me. They know I'm pregnant but I can't use that as an excuse for the next nine months... can I?

What do I do? I don't want to slack off, that is not me, and I sure as hell don't want to lose my job. Yet, the truth is I don't want to go into work at all this week... how sad considering I love my job...

I hope this changes, because I am not happy.