Is this implantation or spotting from Nexplanon???

So I’ve been on Nexplanon since August. I got my first period but not my second or third. I woke up with this in my panties ? What could it be ?? I had cramps last night like period cramps almost. And it’s been hard for me to like poop or pee, like when you’re on your period and it’s hard to poop. Idk can someone please help is it my period after not having one for 3 months ?