Today I Got Dizzy And My Eyesight Was Blurred. My

Today I got dizzy and my eyesight was blurred. My primary said I had a TIA and put me on baby aspirin. I have fairly recently been treated for renal failure which has been improving with changes in medicine. Will the aspirin prevent future TIA's and are there other things I should be aware of? Also my bottle of baby aspirin has an expiration date of 9/15. Will it still be effective and for how long?