My fear of accidental pregnancy is pretty much ruining any sexual encounter I have. I ended up sleeping with a young coworker; she was not on the pill and we just used a condom. It didn't slip or break, but I am absolutely beside myself with fear that she might be pregnant.

Typically, most of the women I've slept with long-term are on the pill, so I've never had a pregnancy scare before, but I am just wondering, how many guys here rely solely on condoms for birth control, and have you ever had a pregnancy scare with them? Effectiveness rates seem to vary from like 82% up to 98%, which is sure as hell better than nothing, but still not great.

Besides a vasectomy (which I am seriously considering, but not yet ready to take the plunge) or abstinence, what can I do to reduce the risk of pregnancy in casual sexual encounters?