Been spotting for 5 days now and no period. i had unprotected sex about 7 days ago. what could cause this to happen?

Unlikely not related: Your spotting is unlikely not related to you not having a menstrual period. The spotting can come from the recent sex, and you can have some bleeding from cervix it it's been irritated. You missing your period can be due to numerous factors including stress and hormone changes. It's very common for women to miss a menstrual period on occasion.