Well, when I was about 3 weeks pg, if that, we (DD and I) met a friend at the playground. I couldn't believe how grumpy I was being, grumpy and short on patience to DD and even grumpy and unable to maintain conversation with my friend. (Which is SO unlike me normally).
Eventually I apologized to the friend for being that way and her response was "maybe you are pregnant" My thought was that that was way too obvious (I really didn't know I was pg yet). Sure enough: pregnant.
Now, at 8.5 months, my patience has definitely been short much of the time. I know it will be hard when the baby comes, but I'm hoping there's a change in my patience level - for DD's sake.