This month i had my period for 3 days usally i get it 7 this month no blood cloths or cramps what can this be help please thank you?

Irregular Menses: It is common for young women to occasionally have their periods last longer/shorter, come early/late or miss them all together. If you continue to have irregular cycles x 2 more months, see ur clinician for an evaluation. See them asap if u develop excessive bleeding. If u r sexually active, consider hormonal contraception, which can regulate your cycles while prevent unintended pregnancy.

Observe: If pregnancy is a possibility, then do a pregnancy test