Birth control, weight gain, metformin and pcos

Stephanie • Hi everyone! I am 33 years old, I have been blessed with 5 beautiful children, 17 year old triplets, a 10yr old and a 6yr old. I have had PCOS for 15 yrs now...

What is the best birth control for pcos that dosent cause weight gain? I have a regular monthly cycle no matter what. Dr says it's my body basically tricking itself saying I'm ovulating but I'm not actually releasing an egg. I am eating low Cal low carb almost keto and starting to loose a little weight. I need to get on some type of birth control but afraid of the side effects.