I'll follow the clues from the B-Girls (Buglady & Beverly) and carry a small kit. I used to always carry one when my transport was a motorcycle for twenty years. I only had to use it a few times in twenty years, but like zonatandem said, it's better to have one and not use it, than drip blood on new bike leather because you don't have a medkit.
Are there some good online locations we can go to, to look at medkits and medstuff that would be practical for cyclists? I would want to also look at ankle wraps like Tom mentioned, that would be good to have when cycling if you've had a recent turned ankle (avulsion, distal tip, fibula), because I think I've been given a weak right ankle for my 50th birthday.