Fertility Ultrasound on Period

I went to my gyno today to see how I would go about making sure my oven is ready for a bun. He told me that they can do an ultrasound tomorrow morning to check everything (already got my annual and everything was normal), and I am going to be on the fourth day of my period. Does anyone know if they will do transvaginal or abdominal? I'm nervous for them to put the probe up in there while on my period