What dose it mean if i start spotting a week after my period?

Hard to say: Sexually transmitted diseases (STD) can cause all types of menstrual irregularities. If you have have unprotected sex (without a condom), then you should be checked for STD. Changes in birth control methods or other hormonal changes can result in breakthrough bleeding. Breakthrough spotting can also occasionally occur without a known reason. If it is recurrent, an evaluation is warranted.