First Ultrasound

I just came back from my ultrasound. I have 5 growing follicles. They are 18,16,15, 15, and 13. I'm very excited but a little concerned because my RE said he wouldn't let me trigger with more than 4. The nurse seemed comfortable that he would, though. She will be calling me this afternoon with instructions. She seems to think that I will be returning for the next day or two for an ultrasound and that I will likely trigger tomorrow night or Sunday night with an IUI day of Monday or Tuesday. Oh, and my uterine lining is 8.5. So, that's great, too!