Feeling down, 😣

My last period was 4th April when I got my implant removed. This is my 3rd pregnancy. I took a test 4th May and it was positive, faint, but definitely there. The lines progressively got darker, the cb digital went from 1-2 to 2-3 last week meaning 4-5 weeks.. On a frer I actually got a darker test line than control. Today I went for my first scan, by period I would be 5 weeks 4 days. I've had scans before with my boys around 6 weeks and seen heart beats both times. However this one was abdominal, and she told me from the scan i was only 4 weeks. She didn't measure the sac, she said there's no point, she said there's no point doing an internal because it won't look any different. I'm concerned as to why I'm measuring so far behind, I could've possibly ovulated late but not almost two weeks late. Going by her dates I would've ovulated around 29th April, however I took 6he first test on 4th May which have only made me 5/6 dpo? This scan was supposed to be for reassurance, not make me more confused😣