When a woman says "you're a bitch," she may be describing your behavior or personality as a bit naughty, cheating, or not serious. This statement may not be malicious, but it may also imply that she is unhappy or dislikes something about your behavior or performance.

However, the specific meaning still needs to be understood based on the relationship between you and the specific situation. Sometimes people will Use some exaggeration or humor to express your feelings. If you are confused by what she said, the best way is to communicate with her and ask her directly why she said that to better understand her thoughts and feelings.