Please help, long period, TMI

I'll keep this short.

I'm on Nexplannon and rarely get periods and never cramp. (Just irregular spotting).

BUT

Came home from 2 month long trip where I was only self-pleasuring. And on the day I came home, I started my period. (Perfect timing right)

So when I finally saw hubby, we had (vag) sex four times in one day/night.

It's been 13 (going on 14) days, and I'm still bleeding, had light cramps on 3 random days, and had uterine lining (that's the thing long membrane right?) coming out on day 12 and 13.

I'm going to buy a pregnancy test tomorrow to see if maybe it was a very early miscarriage (if that even counts).

But I'm worried.