Who is likely the father?

Wow, what a mess! With a normal 27 or 28 day cycle ovulation usually occurs on day 13 or 14. However, sperm can live inside the body for up to 3 days. Sometimes even longer, under the right conditions. The only way of knowing who the father is is if they get a dna test done. Some people believe that marijuana can kill sperm, but really it has little effect. I think she should also be getting to a doctor for an STD test and not be havingunprotected with multiple partners, as this increases the risk of STDs.