Could I be pregnant? Or just stop stressing?

A lot of factors can come into play. Even without soap, if he did even a half-assed job of washing his hands then the vast majority of swimmers probably went down the drain (99.9999). since it only takes one, then yes, there is a slight possibility, but given that the swimmers don't like water, or air, slim would be a generous way of describing. Best bet is to relax (stress can affect your timing) and give it a couple of days. If in 3-5 days you still are a no-show with the main event (so to speak) then I might suggest tracking a test down to be sure.