Are my university choices okay? I'm studying btec.

Hi, I'm studying btec applied science with a level chemistry. I'm aiming for D*D*D and A and want to study Chemistry BSc, but because of btec, my uni options seem limited.
I know a lot of universities accept btec, but I am not sure if they do in practice. I'm aiming for russell group unis (bristol, cardiff, manchester, and nottingham), but one of my teachers has advised me not to opt for them because they dont accept btecs (even though they have stated that they do on their website).
Am I aiming too high? Is there anyone who is or was in a similar boat to mine? please help :/

Many teachers have a very limited awareness or understanding of current University admissions - and give some appalling advice to students. I encounter it regularly, even amongst senior school staff.
If a University states clearly on the course page that they will accept a full BTEC Extended Diploma with a relevant A level - then that IS what they mean. And unless they state something like '3 A levels preferred' then your application will not be disadvantaged because of the BTEC. Universities are governed by marketing legislation - they have to be entirely upfront and honest about what is required or preferred - no 'secret' info.
And btw, many good Unis will also accept a BTEC Extended Diploma in Applied Science without an additional A level in Chemistry - but with specific Chemistry units within the BTEC - Loughborough, Bath, and Leicester as examples.
Aim high - and come back and tell us when you get offers?