Me and my girlfriend had moments together on September 3. By mistake I ejaculated on her panties and she slept whole night wearing those panties. Her periods usually come on 22 or 23 of every month but that month i.e September, they did not come till 25 so she ate papaya and finally her periods came on 28. But again this month i.e October, her periods are late. Today is 31 October and still her periods didn't come. Is there any chance of pregnancy?