If i have sex the seventh day of my cycle, are taking diane pills, and wear a condom, is it safe?

Diane-35 pills are: not contraceptive pills and should not be relied upon for that reason. If you or both wore condoms, and the condoms worked as they should, then you should not conceive. If you have any doubt or experience weird symptoms, some of which likely came from the Diane-35 pills, just check a pregnancy test 3-4 weeks after the date of intercourse.