Acne And Periods? Tmi

So i always know that im about to start my period because I develop acne on my inner upper thighs. Ive been to the doctor about it and have been tested for everything. I have no STDs or infections at all im completely healthy but i still get medium size pimples. Its from right before i start my period to a few days after i finish. The dr told me just to clean very good and keep my skin moist. (Which i do every single day) And I STILL get them. Any suggestions as what i can do? Has this happened to anyone else?

Its hormonal, there's really nothing you can do but seek a dermatologist.