Yes, that is the best approach since they have the experience w/why you may have had troubles in the past (combo pills of hormones). There are many options and as Brandye stated there are creative ways to obtain the Ring, see here in the US it's now commonly used! But apparently it's not part of your NHS.
Good luck!
Additionally; one point I do not understand; here in the US there are several meds which can be obtained through reputable mail order systems. It's shipped to the patient and there are ways around the requirement for a prescription--you just need to be under a physicians care and he/she should be aware of your ordering due to safety reasons. I do not see why a Physician outside of the US could not decide what you need & then have the patient mail order it; thus, making the method/product available. Similarly others have asked about Plan "B" yet live in a remote area or have difficulty getting to the store; again Plan "B" can be obtained through this system using any on-line (reliable) drug store & they ship anywhere in the world. And the cost is much lower (but you have Fed-ex charges). I do not advocate self-medicating by any means; rather, I suggest accessibility to meds via this method with a physicians guidance on what your require.