That's normal. When I got my implant taken out, I had the same thing. It might even take a little while to get your periods back on track and everything should be back to normal in 3 months. You can test in a few weeks if you're unsure, but it's highly unlikely that you're pregnant
You probably are not pregnant. It is normal to expect some light bleeding/bloody discharge after any form of intrauterine device is added or removed.