I would not drink in the very early stages as the embryo is very vulnerable then. Also, stay well away from chemicals and tobacco smoke, especially garden pesticides, hairspray etc, heating food in plastic containers etc. There is now proof that these chemicals can actually affect the future fertility of your unborn child.
Later in preg I don't think 1-2 units of alcohol per week does much harm.
I personally am not sure about running as I just did crosstraining and step with DS, then had 2 miscarriages where I'd run regularly, so it might be bad for some people..
With the worrying, remember hormones are crazy at this stage, and you actually worry more about the birth now than as it approaches. It is easier second time round, and I would heartily recommend mobile epidural...
good luck! Stay on mumsnet!