"Pretty" Pimples
Raise your hand if you love having an increased pimple count around that time of the month!
Hmmm... Alright...
0 hands. No surprise there!
There are ways to help reduce them, though.
Firstly, use facial cleaners. My personal favorite is CeraVe:

This works wonders for cleaning skin, at least in my experience. Test around to find something HEALTHY that works for YOU, though.

Secondly, drink lots of water and eat balanced meals. These will act as damage control, helping to naturally keep your skin healthy. Great if you don't want to buy actual cleansers and whatnot, or need motivation to eat better.

Thirdly, don't overload on makeup! The natural tendency for most is to slap concealor on to hide the pimples. By putting on more makeup, you're actually blocking a lot of pores, and increasing the risk of getting more...

Lastly...
Just wash your face twice daily. That's really the most basic thing you can do to help prevent that monthly acne outbreak is to wash away dirt, dead cells, and excess oils. Once in the morning, once at night.
Make sure to get around your nose, as that's possibly THE most oily area.