Having a skin allergy

Every time my monthly period arrives,I've got some pimples appeared on my face but the last time,I've got big ones ehw!Maybe because I was very stressed in our moved and some problems occured too during that time.Normally my pimples didn't get bigger and many,I was very upset and it freaked me out seeing those acnes.I was even looking for some treatments for acne online.I also read some sites that have informations about skin allergies like acne.Fortunately,now it dissapears gradually.