Talk to your doctor about any discomfort you have during or after sex or any other concerns. Most airlines will allow pregnant women to fly up until week I know all about the risk of lung cancer believe me, my parents tell me all the time , but someone just mentioned in passing that smoking has some negative side effects for women , particularly in regards to reproductive health. In addition to the flu shot and Tdap vaccine, other vaccines the CDC considers safe during pregnancy, but only if truly necessary, are:. Smokers also produce less breast milk than non-smokers. If you're worried, contact your local water supplier to get a copy of the annual water quality report.