[Coffee.]

It's quite unlikely, but is possible. Obviously, if at the end of the month your period is late, take a test. But I wouldn't worry about it.

I would recommend you start setting an alarm on your phone, my sister started doing that to help herself out! And as usual, I will always recommend condoms (Gotta be the crazy condom activist! ). They help for these types of things, I'm terrible about remembering my pills, so it's always good to have that extra back up, and plus they protect against STIs as well.. But I highly doubt anything will happen from forgetting once.