Catherine goes to her local movie theater only to see romantic comedies. Since Catherine did not go to the movies yesterday, there is not a romantic comedy playing at her local theater.

can't tell.

all we know is that if she went, there's a romantic comedy playing.

there might be a number of reasons she did not go.

logically, if
p = she goes
q = there's a RC playing

we have

p --> q
and ~q --> ~p (no RC, no go)

but p --> q tells us nothing about ~p