my 2yr old had grommets put in around 5 months of age the doctor can look and tell u if they are still in, my son has had one fallen out it was sitting just outside his ear in wax i picked it out and it was tiny so if you werent looking for it you would would probaly miss it. There was no blood but he keeps getting ear infections in that ear so he will need them replaced.   

I had gromets put in when i was approx. 9 and 12 years old. From what i can remember i dont recall seeing them at all when they did supposively fell out. All i remember is always having alot of dried blood and goo afterwards and i suppose it must of been mixed up in all that and wouldnt of seen it. Im sure your doctor would be able to see that it has fallen out.