I'm pregnant woman can i use nexium (esomeprazole)?

Yes: Pregnant women can use a proton pump inhibitor in pregnancy. Better is to try antiacids like Tums or rolaids first, then zantac (ranitidine) or Pepcid and if those types of medication dont' work, then consider a proton pump inhibitor. Talk with your doctor first about your heartburn so he/she can know what you're experiencing and guide you as well. Best of luck!

Probaly yes: It is safe, but not adequately tested in pregnancy however prolonged use more than a year make you more prone to osteoporosis and fractures. For a short term to subside the symptoms of heart burn in pregnancy, is safe most likely.