Had unprotected encourse sept 28 & week after my period. (28) cycle. i just found out lastnight white mucus coming out of vagina. can i get pregnant?

Yes: Unprotected sex can always lead to pregnancy. It sounds like you had this sex appx 7 days after your lmp. While this isn't typically a time of ovulation, sperm can live in vagina for 72 hours so if you were to ovulate in 2-3 days, you could still be impregnanted from yesterday's sex. The mucous you saw is not an indicator of pregnancy at all. Could be semen or just vaginal discharge.