Two periods in 1 month?! Help?

Hi girls

So I have been experiencing two periods in one month

Sometimes my cycle I will have 1 period a month then for roughly two months after I will have a period at the start and the end ..

I have only just come off my period a week ago and now I have come on my period 8 days early ?! does anyone else experience this or have a clue why this could be? I’m not on birth control or the pill. I don’t take medication. I use protection with my partner ( plus this happens every month) so I know i can’t be pregnant. I eat healthy, exercise. It’s so draining for my body I feel tired everyday & weak and so rundown and bleeding twice in 1 month is affected my body so much.