There is no contraindication to travel this distance, provided you do not have morning sickness i.e. vomiting during pregnancy, or have not had bleeding following conception.
I would advise a flight plan that gives you a stopover of at least 2 hours in between this long flight. Regarding other travel precautions - consult your treating physician to give you an OK prior to booking your flight. Other problems that can develop during in flight- like clot formation in deep veins of legs due to sitting for prolonged period (which applies to all) can be taken care of by walking up and down the aisle during the flight and some leg exercises (your air hostess can tell you).