at about day 14 in your menstrual cycle you become fertile (day 1 would be the first bleeding day). you have a lot more mucous than usual. you become very sexual because this is your fertile time and you subconsciously dress appropriately i.e. more makeup, jewelry, revealing clothing, etc. just take notice and you will see this is true.

and remember, just because you are fertile for only a day or two, doesn't mean much because you can't be absolutely sure when it is. although studying mucous viscosity, temperature, and calendar patterns can put you in the ballpark. but mucous can hold sperm in for a few days and send it on up on the fertile one.

p.m.s. is a reality. some deny its existence but it can be easily seen if one's menstrual cycle is charted. it's affects vary though but watch out for moodiness. try and talk yourself down and remind yourself that it is purely hormonal.