Lump behind ear referred for ultrasound

I have found a lump behind my left ear about 6 weeks ago and mentioned it to the GP who felt it and referred me for an ultrasound on wednesday. It's really making me anxious as i feel like it might have been here for even longer and i've also lost weight and struggled to gain it back

I was wondering if anyone had experienced the same and it turned out fine? I think i won't be able to relax until wednesday and even then i read it's quite difficult to diagnose for sure with ultrasound so i would prefer they do a biopsy but i don't know if they will

For those who have experienced the same what should i expect? Did it turn out ok?