I saw my gp almost 4 weeks ago concerned with a growth on my

Hi,
I saw my gp almost 4 weeks ago concerned with a growth on my inner thigh that I’ve only noticed as it’s grown a lot over recent months (I ignored it initially as have had a baby and assumed it was a weird weight thing or something). I’ve had bloods taken, all came back clear and doctor put me on antibiotics but also referred for ultrasound. Had the ultra sound 2 weeks ago and sonographer told me there that it looked like an intramuscular lipoma, 10cm and that recommendation report going back to gp would be to have further imaging to confirm diagnosis and rule out anything else.
From my reading of NICE guidelines on lipoma and those larger than 5cm with fast growth, a referral to a sarcoma specialist should be considered to facilitate diagnosis/rule sarcoma out. I was expecting this type of referral but when I spoke to gp’s to query what was happening, they said a letter had been typed up but needed a doctor to mark it as urgent to send it off. 2 days later, I get notification about an appointment at my local orthopaedics dept (no sarcoma specialists) for 2 weeks time. I’m no doctor or expert, but this seems to be a very different to what I was expecting or understood from guidelines. I don’t expect I have sarcom, but I’d like to feel reassured that Im being diagnosed by someone who would know if it def was the not sinister possibility. Have I got this wrong or maybe it doesn’t really matter. Would appreciate views as haye having to call gp wuerying their ways or requesting a diff referral.
Many thanks,
M