had internal scan and blood tests today- negative- but could i still be too early?!

okay so i'm 9 days late for af so technically i'm 5 weeks 3 days today.

i had an early scan and bloods today and they were both negative

although doctor said my uterine lining was very thick at 7.7 mm and that could indicate a forming pregnancy??? (so the scan was technically inconclusive)

however from when I THINK i ovulated i would only be 11dpo today..... do you think i could still be too early for the scan and blood to pick it up?

thanks!