Anyone similar?

So according to Glow I'm 5 weeks 4 days, but my cycle might be more irregular than I thought.

Today I went for my first check up and they said it's too small to confirm the pregnancy so I'm going back next week.

From googling it I'm still not sure if I should be worried or not.

In the hospital they said nothing is necessarily wrong but just that the maths doesn't add up with what I told them about my cycle.

Looking at different things my scan looks more like a 4 week scan with not knowing exactly when I ovulated it's possible inoculated a week later than is average.

Has anybody else had anything similar?