2 BFP then BFN

This is my first IUI. On 3/4 I triggered because my hormones surged then on 3/5 I had my IUI. 9dpiui I tested and got a BFP, 10dpiui I got another BFP, now 11dpiui I got a BFN. Could the two positives still have been from the trigger? I’m going crazy with the nausea and fatigue! I’m also on progesterone.