Confused please help

I’d had lots of sex before I had my implant put in this could of triggered a pregnancy which I don’t show up until I’m around 7-8 weeks on a pregnancy test. Anyway 4 weeks in I had my implant put in with a negative test she said you will be fine if you are pregnant but take a test in 1-2 weeks I started bleeding really light at the start and a normal period would only be 3 days long.

I’ve started having mild but noticeable pains and headaches so went to the doctor on day 4 as I passed a large piece of tissue she said it will just be your implant and never offered any tests etc say 6 and I’m still bleeding heavily with blood clots all in photos could this be my implant or a miscarriage.