iui tomorrow...question about timing intercourse

I'm torn! Got my peak today unexpectedly (thought it was going to be tomorrow) and will go in tomorrow morning for my 3rd iui. My debate is: should I have sex tonight even though the clinic wants us to wait 24 hours between sex and insemination or just wait to have iui and then sex in the evening on Wednesday? It feels so weird to get peak and not have sex!

This is all coming after a 23 week and 5 day loss in May 2016. We have been struggling to get pregnant again ever since

and I'm just stressed. It would be really nice to have a rainbow baby someday....feels kind of impossible at the moment.