My frd had sex and didnt get periods for 3 months 5 days back she got her periods which was usual and lasted for 5 days, now she is not pregnant?

Probably not: Bleeding can occur during pregnancy, but unlikely after this long. She is probably not pregnant. If you want to be sure. Home pregnancy test are available without a prescription at your pharmacy.

Pregnancy: Sounds like she is not, but people can have some periods in early pregnancy. Might still be worthwhile to get pregnancy test.