I been gaining weight and had my period for 3 weeks straight spotting and lightly bleeding non stop not a normal cycle?

See your doctor: If you have continued ongoing spotting and no normal menses, you should see your doctor. If you recently changed medications such as birth control, that could be the reason.

XS menstruation: At twenty-four, it is uncommon to have extended bleeding associated with "menses". Obtain a serum HCG test for pregnancy. If negative, you are probably having non-ovulatory cycles, but see your healthcare provider, since other clinical situations (fibroid tumors, retained placenta, etc.) may be causing this.