The other responses cover a lot of good ground. Without knowing more about your situation, I'm just going to throw some options out there for you to consider:
Acupuncture has been proven to aid fertility. Try to find a practitioner who handles a lot of fertility patients. Also, Chinese medicine may help.
Read Taking Charge of Your Fertility by Toni Weschler. This is the bible of infertility for many women.
Revamp your diet. Cut out refined grains and sugar. Drink a couple of shots of wheatgrass every day. Reduce or better yet eliminate red meat. Eat lots of fruit and veggies. And this works better if you also get moderate exercise frequently.
Like the others have said, the best thing you can do with the money is roll it over. Think of it this way: most people grossly under-save for retirement and end up having to push retirement back for many years or scale back their retirement lifestyle dramatically. Also, you will almost certainly never get around to putting that $3000 back into retirement savings - so once you withdraw it, it will be gone forever.
I think Jess's idea of using the money to pay off debt and reduce your monthly expenses is a very good one. I also have one more alternative to suggest: most plans will allow you to leave your money in the plan when you leave your job. So how about doing nothing for a while until you've found a new job and you're financially stable again? Then you can roll the money over to an IRA or your new employer's 401(k) but still have the safety net of knowing it's there if you need it without being tempted to spend it frivolously.
Congratulations on the baby and good luck with your decision!
