Hey Bluejude,
People that are bipolar really shouldn't be off of meds for any length of time. Having a major manic or depressive episode isn't safe at anytime. Even if you haven't had a bad episode before, your situation could cause on in either direction. Mania can lead to psychosis, and you don't want to be hallucinating stuff when you are pregnant. You didn't say which meds you were taking prior to your pregnancy, or what kind of doctor told you to stop taking them. You also didn't say how far along in your pregnancy you are. Was this a surprise? With all the emotional things that can be affected by your hormones, making sure you are as stable as possible is a good thing. Please check with both a psychiatrist and a gynacologist as soon as you can, as you are already feeling the effects of lack of medication.
I have a cousin that is bipolar, so I'm fairly familiar with the condition. Lithium can cause birth defects in the first trimester, but could be OK during the second and third trimesters, depending on the risks to you versus those to the baby. It can be passed to the baby through breast-feeding, so those taking lithium should only bottle feed the baby.
I would be very interested in learning more details regarding your situation. More information can only help us provide you with the best support we have to offer. Hang in there!!!
Leigh Ann