ultrasound

Hi I went to ER early Friday morning due to me having some red blood along with mucus after using the the bathroom. They did an ultrasound transvaginally. The report read within the central endometrial canal the is a 4mm mean diameter fluid collection that could represent an tiny gestational sac.  There is early decidual reaction around the sac. There was no yolk sac, fetal pole, or heart beat that's could be determined. Going by lmp I should be 5 weeks and 4 days. Going by the date of ovulation I'm only 4 weeks 6 days. I'm so confused and googling things only makes it worse. Please someone help!!