IUI with PCOS

I did an IUI February 15th. After taking Fermera I did a vaginal ultrasound the day before and saw one follicle on my right ovary and two on my left so it was the right time. Now it’s March 2nd and I took a pregnancy test because I’ve been so anxious, nervous, and scared. It said negative but my sister and best friend said that it doesn’t show up on a pregnancy test that you’re pregnant at just two weeks unless you take a blood test. I start my period March 4th so should I wait till I’m three days late to take another because it’s too soon right now? I still have hope that it’ll change. Has anyone ever experience PMS before they got pregnant?