Consent must be given before any sexual act…Importantly, consent must remain in place for the act to continue. She has no obligation to continue down a path of sex, if she changes her mind, regardless of the nature of the relationship (including BDSM).
“I’m not sure” is NO
“I don’t feel comfortable” is NO
“Maybe we should wait” is NO
These are not triggers for you to be more persuasive, to pressure her, or to be a bully. STOP!
Also remember, someone cannot give consent if they are asleep, unconscious, drunk, or drugged.
Read more about Safe, Sane, and Consensual here.