Trigger and IUI is this a false bfp? *Update

So I did a trigger Saturday the 7 in the afternoon and a IUI very early Monday morning. I’m wondering if this is still the trigger shot? We have been trying for over 4 years and this is our first trigger and IUI. I held out to today on taking the test and it is FMU. I plan to test again on Friday but I hoping that this isn’t the trigger.

So I have been taking test since this one and the line has gotten darker!!

Now I could really use your help with how to surprise my husband. He gets back 4/28. I can’t decide if I should surprise him at the airport or at home??