I take it you mean your first "period" as in that period consisting of about one week every month when it can be very annoying to be female?
It can vary greatly from female to female, some girls have a "proper" period with blood, cramps the works, while others build up gradually.
It tends to start with discharge from the vagina, normally whiteish/brown, which is then followed by what they call "spotting". Spotting is literally brown spots in your underwear. Some girls go through months of spotting before having a richer flow.
Periods can be associated to cramps as well, it would be in the lower part of your stomach, just around your pelvis area
Some women also get flustered, cranky and/or weepy because of the hormones, but that's also part of being a teenager. If you feel unusually emotional, it could be a sign that things are changing.
If you have brownish discharge or spots in your underwear, it tends to be a pretty sure sign you're about to have your first period.
See your doctor.
A drought.
It takes 27.32 days
Ancient Times.
Butt
the first signs of slavery was in Virginia
First Signs of Frost was created in 2004.
First signs are stumbling and difficulty climbing stairs
Your peiod was due on a certain date. You count the weeks or months since that date.
Vomiting
vomiting
At the end of the nineteenth century, luminous signs were a new phenomenon.