ANSWER:
The Prophet (peace and blessings of Allaah be upon him) said: “From one ‘umrah to another is an expiation for whatever (sins) come between them, and an accepted Hajj brings no less a reward than Paradise.” Narrated by al-Bukhaari, 1773; Muslim, 1349.
All minor sins are forgiven. If during umrah you repent sincerely from major sins, even those would be forgiven by the Will of Allah.