Heavy period or early miscarriage? HELP!

I am 17 years old and on Sprintec bc. I skipped my last period by going directly into the next pack of my active pills and for the first few days I did not bleed. However, I slowly started spotting and then lightly bleeding. After a few days I was full on bleeding with it only getting heavier. Out of nowhere, I started bleeding heavier than I EVER have and I've ALWAYS been a light bleeder. I have had around 5-6 blood clots the size of 1 inch to 3 inches, which I've also never experienced this severely before. I put on a fresh pad this morning and after 4 hours in the car was soaked in blood, the seat covered in blood, and had even more blood clots. The bleeding feels out of control and definitely abnormal for me. I am sexually active yet take my pills perfectly. I am wondering if this is a result from my body not responding to skipping my period and the built up blood releasing OR if this could be an early miscarriage. I am still taking my active pills throughout the bleeding. Any advice or knowledge would be appreciated!