Hi. I Am 30 Now. About 6 Months Ago My

Hi. I am 30 now. About 6 months ago my period started changing. I get a 7 day period every 2 weeks. I have had the mirena for about 2 years. My periods are also making me very sick with a lot of pain and my IBS is 10 million times worse then. Now for about a week I have been getting hot flushes in my vaginal area.
I saw a GP 2 weeks ago and he suggested seeing a gynae. I asked him what the chances are of peri menopause and he laughed it off. He said it's most probably my mirena.
Any advice please?