I know this is a strange question, but does anyone know if there is a treatment (whether by pill or shot) to prevent a pregnancy that may have occurred? I have a pure bred dog and she just went into heat last night. I wasn't sure if she looked swollen or not last night, so I didn't want to board her up in a pin in the basement until I could tell for sure today if she was in heat. When I went out to check on her this morning, a random stray dog was mounted on her and they were "locked Up." I am not even sure if she could get pregnant this soon in her heat since it has just now been 24 hours into her cycle. She might not even be fertile yet. But if this dog did ejaculate in her and she is fertile, I was wandering if there is a medication that could keep her from conceiving. Something similar to the "morning after" pill for humans. If there is anyone reading this that is knowledgeable about dog breeding and could help answer my question it would be appreciated.