I had unprotected sex a week ago. I've been on monist at 7 for 3 days for a yeast infection and today I had a pinkish discharge, could I be pregnant?

Not how it works. A pinkish discharge is in no way an indication of pregnancy. But, having unprotected sex when you are not on your period means you are at risk of pregnancy. If your next period does not start then you may want to consider getting a pregnancy test. Doctors never, ever, guess when it comes to diagnosing pregnancy.