Annoying period

Niamh • I'm Irish so there is a high possibility that I'm an alcoholic 😏🇨🇮
Okay so I'll start with I have the implant contraception and I don't get periods normally, but every 3-6 months I would get one that lasts for ages!! So I recently had an extremely heavy period from the 8th of December until the 26th - now it's started again and it's really heavy!! My boyfriend thinks it's because of all the sex we're having and he usually finishes in me, so several questions;
1. Is it because I'm having so much sex?
2. Is it another period?
3. Is it my implant?
4. Or is there a possibility that I could be pregnant?