Weird results at early ultrasound

Just wondering if anyone has similar experience as it is driving me crazy!
Went in for an early uktrasound, mainly to nail down the date as I have a very irregular and short cycle. I knew possible DOC for June, but was thinking it could have possibly happened in May. So if anything, I thought I was possibly further than expected. 
I go to the appointment at a pregnancy center-this is important because they don't do any diagnosis, which is why I was left hanging...anyways, knowing I am at least 8wks 5days on Monday 8/8. 
First unsettling thing, was she dated me at 7wks 2 days. I know this is completely impossible as I tested positive on 7/6 after my missed period on 7/4. Again, I know my DOC was either 6/22 or 6/24 and I have a 24 day cycle. But they didn't listen to me once. 
Second weird thing was that "something else" kept popping up at times. It would be close to baby in some frames and then not visible in others. It was pulsing as well...but the ultrasound tech seemed completely baffled which made me not feel like I was in good hands. She chalked it up to a possible blood vessel, a reflection of baby's heartbeat, or another human...how reassuring. 
Sorry for the novel but I guess I'm asking-has anyone had either of these things occur with them and it turned out to be nothing? This is my third pregnancy and have never had either issue happen.