Planted seeds return into items without breaking them.

So, I started with 5 seeds and i planted them and Then like 2 mins later 2 seeds turned into entitys/items and I did NOT Break them because i was away so i replanted them and the next real life day they were still there. Then i went mining for about an hour. Then i come back seeing that 2 seeds were missing... Then i craft my stone pickaxe and then... another seed turned into an entity/item.