I felt so happy when I ordered a cheese pizza in my second trimester, but honestly, eating it once in a while kept me sane! Just make sure it is piping hot when you eat.
I asked my hospital's nutritionist during my checkup and they said home-made pizza with fresh cheese is best. If ordering from outside, choose a reputed place to avoid infection.
My doctor said occasionally having pizza is perfectly fine as long as the veggies are washed and cheese is pasteurized. Just avoid raw or undercooked toppings.
If you are craving it, make sure it is cooked fresh and the cheese is pasteurized. Still, better to ask your gynac if you have any digestive issues before eating outside food.
Of course you can, just don't eat it everyday. Order from a hygienic place, ensure the cheese is processed/pasteurized, and enjoy your slice without guilt.