Can you get pregnant from having sex and sprem ejaculated four days before your period?

Yes: If you don't use contraception you can get pregnant.

Less likely: but always possible. If you miss your period do a pregnancy test, If you get your period you are not pregnant. If you do not want to get pregnant get on birth control and use condoms every time as a backup measure and to protect yourself from STD's.

Not likely: but possible. Ovulation usually occur 14 days before the period. The egg released will not survive that long