I had my period for 2 weeks, should I go on birth control?

Possibly. Irregular menstruation and prolonged bleeding can often be well controlled with hormonal contraception. Depending on eligibilty, this can range from cyclic methods, such as birth control pills, ring, or patch. Other methods, such as depo-provera, Mirena (levonorgestrel) iud, can also be effective. Consult with your md.