I am a girl of 18 years.. i usually get my menses on time..but this time it is 9 days late.. the last month i got them on 23rd of may ..and now 23rd of june has also gone..its 2 or july now.. i don't know what is the matter.. well near 27 june i started feeling pain in my abdomen.. the menses pain.. it was like they are about to come..but there was a party thrown that day at my friend's house and i had beer..not much..but i had.. from that day the i can't feel the pain ..and it doesn't seems like it will come.. i'am really tensed... please help out...