Help 😔

I'm on implanon. I'm on my first period since getting the implant. And now I'm  peeing more, tired like all the time. 
My periods been going for 10 days now. (Twice as long as usual) it started out stopping and starting. And then it got really heavy and was black. Now it's nothing. Then heavy then nothing again and it's blacky/red now. 
I caught a train a week ago. And I got motion sickness. I never get sick on trains or motion sickness for that matter
I'm just really worried. Could I be pregnant? I'm only 16 and I don't want a baby