If you think you are in peri meno, it's important your GP treats this. The options are HRT or one type of the CCP- Qlaira- which is similar to HRT but sometimes better for younger women as it will help regulate cycles.
I suggest you read the NICE Menopause Guidelines which are for us and drs! These were published in Nov 2015 after a long consultation with menopause experts. ALL Gps should know and work within the guidelines.
NICE MENOPAUSE GUIDELINES
In particular read Diagnosis- linked above.
The British Menopause Society (website under that name) are aware GPs lack of education around menopause and run training workshops all year round- but they are not mandatory.
They show you what your GP should be doing- and not doing.
In peri, it's accepted that you often have erratic periods/ longer/ shorter cycles/ more/less bleeding. This is usually the first sign.
You may not however, but you could have other symptoms like flushes, mood swings, insomnia, weight gain, anxiety etc.
NICE makes it clear that in women under 45, blood tests (FSH levels) should be done (over 2 months not just 1 test).
For women over 45, the guidance is treat the symptoms if they show peri menopause.
The reason for no blood tests on women 45+ is that a) they are unreliable due to fluctuation hormones and b) they are a waste of time and money because the signs are clearly perimenopause (unless there are signs of other illness like thyroid issues.)
If you are in your 40s, you are within your rights to ask for HRT or the CCP to help your symptoms, or counselling, or CBT, or anything else mainstream that may help you.
If your GP won't listen, be more insistent, or change to another dr.
Sorry for the lecture! I'm a health writer and have covered this so many times in my work, and spoken to UK consultants, who are fully behind the guidelines, but women need to educate GPs at times!