Should I take a test?

Tasha • 17, I`ll be 18 in June. Me and my boyfriend of a year are trying to have a baby together.
I haven't had a period In 2 months, last month I took three test and one had a faint line, a week later I took another one it was negative then I took one more just to make sure and it was also negative. Since then me and my boyfriend have had unprotected sex, but I'm not sure when I should take another test. Please help.