Are these size clots normal?

I'm a virgin. I'm only 15 years old and I get really big clots during my period. They're as big as putting your forefinger and thumb together into a circle shape, sometimes bigger. I have ovarian cramps throughout my period, but they worsen whenever a clot is about to pass. I can feel when I have a clot, because I start hurting. I don't know if it's normal or not. It just seems really big. What should I do about it? My period last 6 days and I usually have spotting for about a week before my period. The flow I have is average, I think. I'm not really sure if it's average or heavy since I don't really know how much anyone else bleeds. My mom has a lot of trouble with her period, to the point where she used 12 tampons in about 3 hours. I don't want to be like that. Some advice, please?