Pregnant and flying.

Hi all. I'm in the early stage of my pregnancy. I'm not too sure how for along I am because according to my LMP, I'm supposed to be 10 weeks. I've gone in for a scan because I've been having quite frequent spotting and one time, it was with severe camps. The gynae said he couldn't see anything but the pregnancy sac in the womb with no signs of a fetus yet. So he said I'm probably about 4-6 weeks and the spotting could be a sign of threatened miscarriage. I work as a cabin crew and I'm wondering how far along should I continue to work until I declare to my company that I'm pregnant? Any advice please?