according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>, I am 9 days late for my period. In the month of September I didn't have a period. It didn't start until like the 3rd of October and ended like the 7th or 8th. I had unprotected sex with my boyfriend about 4 weeks ago and he came inside me. I took a pregnancy test last week but it came back negative. Should I take another test this week if my period doesn't start soon?