AF? Cycle Buddies. Cramps

Stacy
I am new to this app and to this community. I am 31 years old and have been trying to conceive for 6 months. 
My period is due on the 9th..so I guess cycle buddies are people who are suppose to start the same day? 
6 days until I am suppose to start and I am really crampy today. Is that bad? Does that mean I am probably not pregnant, since my boobs aren't really sore and they usually are by this time of my cycle....
And what does AF mean? Is it aunt flow? Any help would be appreciated.