Which position is safe for 2nd trimester?

I went for downsymdrom screening today. My fetus position was face down the whole time. Baby barely move to get captured, I have to go for a walk and come back to the ultrasound room to try three times also hard to get it move the fetus. Luckily one senior staff come in and help to use another method then successful. My husband worry that if the fetus facing down will have more chance of miscarriage and I am also a bit worry. Idk because of he facing down position, my belly was more heavy and very hard to move myself. Can some experience person tell us is it safe position if the fetus facing down during 2nd trimester, please? Thank you.