What does it mean when u have a lot of white discharge and watery discharge a week after protected sex?

Nothing necessarily: if your question has to do with the possibility of a pregnancy then, the meaning of the discharge can only be known after you miss your next period, get a home pregnancy test and find out the results. The other thing that a discharge can indicate in a woman following sexual relations is that of an infection. Protected sex reduces but does not illuminate chances of sexually transmitted infection.