Spotting in early pregnancy can be quite normal. You are pregnant. The best thing to do would be to make a doctor's appointment right away and get checked. Spotting can also be an early indicator to a miscarriage so it's best to get checked.
btw, it's not implantation bleeding. That happens before you are able to get a positive as it's implantation that triggers your body to realize it's pregnant and to start to produce the pregnancy hormone.