So My Girlfriend And I Had Sex About 4 Weeks

So my girlfriend and I had sex about 4 weeks ago, a week after her last period. We went once with a condom, went straight to bed, then woke up and went again -- this time without a condom. She is on the pill and I pulled out, so I know the chances were low, but my fear was since I didn't urinate before ejaculation that it may have affected things. She is now a little over a week late for her period, but she said that she had some cramping last week. We have been taking final exams and are both very stressed, which she thinks is why it's been late. Nevertheless, we are both a little stressed now about this too and are unsure if she may be pregnant. Any thoughts or advice is greatly appreciated.