Could my girlfriend be pregnant?

Me and my girlfriend had PROTECTED sex. One of the times a couple months ago before I put the condom on I presumed around, not in her. She had her period on schedule a few days after that. A few weeks later we did it completely protected. I am 100% certain nothing got in or around her, but a few days after that she got nauseated, really stuffy, and muscle soreness. The doctor said it was a virus she would be over in a few days, which she was. And her period came on time after that, but it only lasted 3 days, which is shorter than normal. She said it wasn't lighter or heavier and everything was the right color. A few days after that she had a pink discharge come out for about 3 days. The only other potential symptoms are a headache and red itchy eyes, but she's been at the beach so that could just be from dehydration and the sun. Could she be pregnant?