Can a girl be pregnant if she is virgin but penis get inside vagina half only in which penis got up and down around 8 times without releasing sperm?

Misconceptions. No one is a virgin after partner sex involving intercourse.The excited penis has mucous secretions that contain sperm, so any contact of that penis with the vagina can deposit enough sperm to cause pregnancy, even just 8 times.Just because you didn't release the main load does not mean you didn't leave sperm behind.Pregnancy risk is less than when the main load is left, but still possible.
Yes. Birth control and condons are the best way to avoid pregnancy.
This is intercourse. There is enough sperm in the secretions from the penis even without "ejaculation" for her to get pregnant.
Low odd, but... The odd to conceive under your described profile should be as low as zero in considering high fastidious requirements for sperms to survive and swim to fertilize a timely waiting egg in Fallopian tube. Nonetheless, still do HPT one week after missing period and repeat it in another week if the first HPT is (-) & still in doubt, since there have been no 100% reliable contraceptives but abstinence.
Not likely but 'yes' If there was any fluid released by the male (pre-cum)), it can contain sperm - not as much as an ejaculation, but enough. Also, very healthysperm even near the vaginal opening can swim into the canal and if the timing is just right, conception can occur.