PMDD & Pregnancy

At around 13 when I got my first period I started having trouble about a week out of every month-right before my period. I would get in trouble at school and my relationships would struggle because my moods were so up and down. It was almost an experience of depression monthly. After I had my daughter 12 years ago, I was put on Zoloft for Post-Partum and I was on it all the way up until I found out I was pregnant with baby #2 this year. (So for a total of almost 12 years). I don't know if the Zoloft truly helped me and I did go off it several times throughout the years as I didn't want to be medicated all my life. I never actually tried what some doctors recommend for PMDD and that's taking the Zoloft for just the week before your period. I never did this because it didn't make sense to me as it takes 2-3 full weeks for the medication to even take affect so how could this work by taking it for a week and then not for 3 weeks every month? Long story short, my mood is now so even keel and I feel happy. I'm 18 weeks Monday and while I had a few moody times in the early weeks, overall I have just felt wonderful. My OB says pregnancy has a way of evening out our hormones. That was my problem-they were up and down with my cycle. I'm worried about after I deliver and wondering if anyone has experienced PMDD before, during, and after pregnancy and how it was for you.