4 days before expected period. white milky discharge with no odor. could possible be pregnant. is the discharge another sign if pregnant?

Possibly: Unless you are trying to become pregnant, this discharge is most likely just a pre-cycle discharge. It could, however, be related to pregnancy. If you have had unprotected intercourse, and your period doesn't come on time, then you will need to check for pregnancy. You can start checking as soon as your first missed day. You may have to recheck a few days later before a positive test shows.