acne!! help!!

I just got off my period idk if that effects anything..but I have bad acne all over my back, shoulders, chest, and some on my neck and face! Yes near my period I do usually get some pimples but nothing like this! And I put lotion on every night aveeno for sensitive skin, I've put it on for months and haven't broke out , but some reason I am today! Can any body tell me what it's from? And how to make them go away ?