False negative?

Hello I had my first IUI done October 7. Along with a trigger shot and clomid 100mg. I have also been taking progesterone pills vaginally since my IUI my RE told me to test today, which would be 14 days after the trigger shot. I got a negative. My period is not due until 5 days. Is there a possibility I got a false negative? I'm gonna test again after my period is due. Need some positive thoughts, prayers, and advise. Thanks.