Endless Period

I was flying home from overseas and there was lots of long layovers and weird times and all that and as a result I missed about 3 pills. The next day I took them all to catch up but then my period started and I thought that's weird and annoyingly about a week early but that's just because I missed the pill. Now I've had my period for about eight days which is far too long as normally it's only there about five days and it is relentlessly heavy and shows no signs of slowing down. What is happening and when will it stop? Should I go to the GP or just ride it out?