touching - making out - foreplay - initial penetration - intercourse - ejaculation - withdrawal
Definitely, getting a no (or just not having consent generally) any time before penentration, and then proceeding to penetrate, would be rape. After withdrawal, consent can not be retroactively withdrawn. In between would be a moral gray area, but I've never heard of a person who was convicted of rape when the woman acknowledged she changed her mind after penetration.