If a pap smear test involves taking a sample with no feelings of desire, then it does not break your fast.

You have to try hard to give up this habit, and take your thumb out of your mouth every time you realize that you are sucking your thumb. Whatever happens because of forgetfulness will not affect your fast.

Eye drops, ear drops, ear syringing, nose drops and nasal sprays do not invalidate the fast so long as one avoids swallowing any material that may reach the throat.