What Causes Irregularities In Menstruation?

Her peiods are normally on 26th. On 13th my girlfriend and i did not have sex... but i ejaculated when we were kissing. Wiped it with a cloth using my hand.... After wards i did touch her vagina and even the finger was inside it.... immediately after that as a safegaurd took i-pill. after four days she got bleeding for three days. Now her normal periods are delayed by 8 days? any chance she is pregnant?