I found this thing outisde thats white with swirly stuff that are pink, its in the shape of an egg, what is it?

i was outside watching my little sister when i found this cirular thing that was white with, well i guess swirlyish pinkish designs, and i no this sounds extremly retarded, but i am really afraid and i keep on thinking its a dinosaur egg, and i really want to know what it is.... like i think its an egg of some kind..... but i dont know, so if anyone has an idea of what it is, please post an answer!