We are collage going students. On 21 of April we had protected sex following which we wiped everything and  inserted penis for once. I am girlfriend was supposed to get her periods by now but she hasn't and we are afraid that something wrong has happened. We didn't took any pill after that as we thought we wiped the cum so it won't matter. Her last period came on 7 of April, she has PCOS and she is taking too much te sion after this incident. Please suggest what to do.