Your symptoms of pregnancy will usually appear anywhere from the first week of your expected period to 1-2 weeks after your first week of expected period. Your first signs of pregnancy most commonly include missed period, tender/swollen breasts, change in color of the breasts, fatigue, nausea/vomiting, increased sense of smell, and weight gain. Here is a link to a website that will calculate the probability of your pregnancy: http://www.thepregnancytest.com/
You cannot.
By taking a pregnancy test
You would know if you're pregnant by taking a pregnancy test. A pregnancy test can be taken from two weeks after intercourse and doesn't require you to know when your period should have started.
In theory what you just siad makes no sense at all because you dont need a test if you know your pregnant as the first part suggests.
The only way to know is by taking a pregnancy test.
By taking a pregnancy test. And you should also speak to your mom. Sex is illegal at your age.
By taking a pregnancy test.
The only way you would know if you are pregnant is by taking a pregnancy test or getting your blood drawn and checked for a beta hcg level.
You cant know without taking a test to check for HCG. If you have an ultrasound scan the baby can be seen, later the fetal heart can be heard by Doppler, and later still the baby can be seen moving.
Take a pregnancy test, which will certainly be positive if you're three weeks pregnant.
Ok you need to take a test. Do you have cramps like your cycle is going to come and you know its not and having moodswings
The best way to determine pregnancy is always by taking a pregnancy test and seeing your health care provider.