We were in the pool. I barely entered in her, but I am scared of precum. She took plan B after 22 hours

Me and my girlfriend were in the pool and I barely entered her maybe an inch I was scared of precum so she took plan b 22hrs later her period was due 2 weeks after that but she had it a week early she had bad cramps for like an hour then she bleed for 4 days she has had no other symtoms could she be pregnant