I'm having a diagnostic ultrasound on Monday. However, my doctor did not specify to me if this ultrasound will be external or trans-vaginal. Monday will also be the heaviest day of my period, and I was wondering if trans-vaginal ultrasound can safely be done while a woman is menstruating. I don't want to make things unhygienic or messy for the techs, so I was wondering if I should reschedule. Edit: Ultrasound is to look for endometriosis/fibroids/PCOS, if that info is pertinent.