What are the lumps in my groin?

When i was playing football, i felt a sharp pain in the crease of my thigh, it was really painfull, after about a week the pain went , but the lump stayed, i have two more lumps now, they are all movable and arnt painfull, they feel like they are attached to something, could it be a hernia, my dad got one a few years ago? I am 14 by the way and it is really scaring me, it has been there for 7 weeks now and i am very scared it may be cancer, i dont know how to tell my mum and dad, PLEASE HELP!!!