i just don't know why the ultrasound tech would say that...

My little nugget at 7weeks and 1 day! So, I have always suffered from irregular periods. I had issues getting pregnant the first time, but it happened and I now have a beautiful 2 year old girl. I lost a bunch of weight and BAM! My periods started to regulate. Hubby and I were ready for baby number 2 and actually got pregnant on the first try! So, my last period was on Christmas Day. Meaning that I should be 8weeks and 1day--IF I had a "normal" 28 day cycle. But my cycles are anywhere from 34-36 days long so I do not ovulate on day 14. Anywho, so my ultrasound tech tells me "you must have your period dates wrong because you can ONLY get pregnant 2 weeks after your period." I'm sitting here like.. "did she really say that?" I mean, we all know that not everyone ovulates on day 14.. right? Some people ovulate late.. or early. I guess I was just shocked that someone with her experience would think that you can ONLY get pregnant two weeks after your period. Am I wrong? Just wondering.