HCG trigger shot and vaginal bleeding

Kathi
So I just went for my mid cycle ultrasound and I have 2 good follicles ready! They gave me an hcg trigger shot in preparation for an <a href="https://glowing.com/glow-fertility-program">IUI</a> tomorrow. About an hour after receiving the shot I went to the bathroom and I noticed a small amount of bright red blood on the paper. There were 2 small drops of blood in the toilet as well. The Internet says that bleeding and cramping can be common during the ovulation process after an hcg shot. But within 1 hour?? That seems awfully fast! I called the office and they said maybe it's trauma from the ultrasound or maybe just hormones and I'm ok to continue with <a href="https://glowing.com/glow-fertility-program">iui</a> tomorrow. It just kinda took me by surprise...I want to know where the blood came from. I asked the nurse if it could be from a follicle rupturing and she said no! What else could it be?? Has anyone else experienced this? Thanks a lot!