How will I know if my IUD falls out or rips through my uterus?

The doctor said that since my uterus is to teeny (even after having 2 kids) that my body may reject the IUD but we both thought it be worth a try. Then he gave me a speech in the order of checking for the strings and to keep contained by mind that it could break through my uterus. How the heck will I know if this happens? I can't grain those strings for the life of me, I don't know where on earth those are! I just get the thing put contained by today so I am curious to see if it works out...any suggestions?
Answers:

Premature Ovarian Failure and douching?

if it breaks through your uterus you will have vaginal bleeding, sharp pains and such, you will know.

Infection that won't move about away? what to do?

Keep feeling sometimes the strings appear to curl up. When I first had mine placed my cervix be up so high that I have to ask my husband to check them.

I believe if it perforates your uterus you will be within pain.

The things my Dr told me to keep watch on for when I first had my placed be severe back soreness and a change contained by your discharge.

Females please help?

I have the same experience when I have mine put in. I could
not find the string, and I really started to worry.
When I see my doctor, she checked to make sure it was
still at hand, and told me that she had cut the string to short,
so I be unable to check for it.