Actually J., Zoloft or Prozac can be used while pregnant or breastfeeding. You kind of have to outweigh the risks and the benefits. Pregnancy and delivery hormones can make you feel more depressed than usual and with your history of depression, you are more prone to feelings of depression.
this site talks about breastfeeding and antidepressants:
http://www.kellymom.com/health/meds/antidepressants-hale1...
I know how overwhelming raising a family can be. With this current pregnancy I did have feelings wanting to be isolated or just not wanting to do the things I needed to do for my family in the 1st trimester. My husband has major depression with bipolar disorder, so it is something that our whole family lives with everyday as well.
If it's something you think you can manage without medication, then good. Are you going to a therapist? It seems like psychiatrists as well as patients are more eager to try a pill than to try psychotherapy. My husband and I feel that they go hand in hand. And personally, I think there are probably more people that can actually do with just the psychotherapy alone. Of course it depends on the chemical balances in each individual.
If you need someone to talk to, let me know. Hope this was helpful.