Can you get pregnant on birth control? Is this a miscarriage or is this normal for nexplanon ?

I was bleeding for over a month and for 4-5 days I had heavy bleeding I bleed through a pad within an hour each time n I’d bleed thru my pants n even on the bed over night n I would pass these blood clots like 6 a day for those 5 days during the heavy bleeding and they were huge and I’d have to dilate to even pass the clots it was too much pain I could feel them coming out so I’d rush to the bathroom im not sure if this is from the nexplanon I’ve been on for 4 months already or if I had got pregnant on nexplanon and my body rejected it? It sucks because I was on holiday back home and don’t have health insurance in that state anymore so I couldn’t go to the hospital 🤦🏻‍♀️