It’s perfectly normal to carry on working till the onset of labor as long as there is no discomfort… carries on with all your activities such as walking, swimming, sex and yoga.
1) Start on folic acid (5mg) at least four weeks before conception. This reduces the risk of congenital defects.
2) Once pregnancy is confirmed, start off on multivitamins. Discontinue for a few days if nausea aggravates.
3) Don’t make major dietary changes. Eat whatever you like but break it into several small meals. Large meals will make you uncomfortable as the physiology of the body slows down during the pregnancy. And yes, you can say no to milk if you up at its smell. Protein powders and dietary supplements are an unnecessary fad.