It sounds good to me in the sense that the medication is taking the edge of your distress, and now you should be doing the psychological work of adapting to your newest child and the role this child plays in your life plan. Don't count on the medicine to mask the adaptive work you need to do consciously.
I'd say the doc is not giving the med enought time to work before he/she ups the dosage. It's been my experience and I've been told this plenty of times by my psych and the pharmacist that these meds take anywhere from 4 to 6 weeks or longer to take full effect. A week or two just doesn't seem that long of a time. Is your doc a psychiatrist?? If not, you probably should go to one for this.
Seems to me like your doctor is just adding more dosage because you 'feel' more depressed. I've been in your situation and I stopped taking it cold turkey about 2-3 weeks ago, and I can't really say it was an easy task, it was VERY hard but, with will power and the right direction and plenty of support you'll be fine.
I just started taking 10mg of Lexapro last week.
I have GAD.
I have been feeling better already and they told me it would take a week or two to kick in.
I was on Zoloft for about 9 months last year and that took about a month to kick in.
I will let you know how this feels after a week or two and if I experience my symptoms again.
My doctor told me I will only need to take the Lexapro for 3 months.