Not to reiterate what's already been said, but what is done is done.
My personal experience is this: I'm an alcoholic. Unless I have a program of recovery, a design for living, nothing at all will stop me from picking up a drink.
I remember when I first got pregnant, I thought: This will fix me. I won't be able to drink for 9 months. One of the reasons I was glad to be pregnant was because I thought it would solve my drinking problem. If I had made it through my pregnancy, it would've been the longest stretch of sobriety I'd had in over ten years. I was 24 years old at the time, and I was a daily drinker. I made it 4 months and then I drank. The guilt was unbearable. I made it a few more months and went on a binge. I felt so utterly ashamed and helpless. I just couldn't put it down completely.
I'm not proud of having drank while I was pregnant. Today, when I give a lead, sometimes I will use it as an example of having lost the power of choice. I did not want to drink while pregnant, but I was an alcoholic with no mental defense against the first drink. The thing about alcoholism is this: once a person crosses that line into full-blown alcoholism, will power just doesn't work. I don't expect others to understand it if they haven't crossed that line. But I did, so I understand what it's like to NOT want to drink so badly because you know you're pregnant, but you do it anyways because you just can't stop.
The only suggestion I can make besides getting honest with your doctor is to get honest with yourself. Drinking while pregnant is a HUGE sign of being powerlessness over alcohol, wouldn't you say? What finally helped me quit for good and all is this: I went to AA. I got a sponsor who practiced the 12 steps. She guided me through those steps and I was as honest as I could be at the time, every step of the way. That's the only thing that worked for me.
I'll keep you and your unborn child in my prayers.