After only three circuits: The four-circuit threshold has not been reached; intercourse invalidates the Umrah, with completion, make-up and one sheep due.
After four completed circuits: The next clause says intercourse does not invalidate Umrah, although one sheep is due.
The threshold of four relates to this question of invalidity; the normal tawaf still consists of seven circuits.
Opening interactive controls...
Bab Jinayat al-Muhrim — Intimacy, Invalidity and Compensation (Part II)
After only three circuits: The four-circuit threshold has not been reached; intercourse invalidates the Umrah, with completion, make-up and one sheep due.
After four completed circuits: The next clause says intercourse does not invalidate Umrah, although one sheep is due.
The threshold of four relates to this question of invalidity; the normal tawaf still consists of seven circuits.