How will I know when my girlfriend will get her period?

hey when will I know when my girl friend is going though her period??? And what can I do to make her more comfortable going through it???
THanks

Awww...that's very considerate of you! my boyfriend ususally knows when I get my period when I start getting really moody and emotionall.Well actually , the cramps hurt so bad anybody would know.
SO maybe if you see your girlfriend having the same sympthoms then she is oh her periods.But you know you could just ask her straight away.There's nothing to be shy of.
Don't pick a fight with her when she's on LOL!try not to do a lot of activities if she has cramps.
well that's it from me.I hope it helps!

That SO sweet that you actually care about making her confortable through her period. Most guys don't care. She's really lucky to have you.
And how people usually know when I;'m mon my period is because the cramps hrut so bad it;s just to hard to hide the pain. But then again, some girls don't get really bad cramps.
But she'll probably act different around you when she on her period. She might be a little moody and possibly mean. I am. lol

Awww...thats sweet most guys dont care they leave you for the week untill you come off LMAO just ask her its nothing to be scared of every gal has it
and yeah she would be moody and I wouldnt pick a fight when she's on, just cuddle and watch a film = ]

lol my boyfriend asks me alll the time if im on my period and I tell him not to cause I yell at him cause im so moody so if shes like moody you'll know