I had unprotected sex with my girlfriend on 6th day. i.e her periods started on 20 and we had sex on 25.I don't think I ejaculated inside her,after my sperms came out I cleaned everything with water.after some time she rubbed her vagina over my penis.are there any chances for her getting pregnant if sperms might have entered?please help

There is a good chance that enough sperm was left in your Girlfriend that pregnancy is a possibility. Pull out and douching are not reliable means of removing sperm or preventing pregnancy. There is enough sperm in pre-ejaculate that pregnancy is a possibility. The best way to know is to wait until your girlfriends next period. If she misses it by more then 2 weeks then there is a good chance she's pregnant. Until that point it might be good to re-evaluate your contraceptive techniques and maybe change up to using a condoms or hormonal birth control.

To add to what Craven said, douching actually ​increases the risk of pregnancy as it propels the sperm upwards into the uterus.