Well, obviously this is one of those situations where no matter what we tell her about personal experience as parents and how hard it is, but especially when you are young, she is going to do it anyway. She's going to have to learn it the hard way. So I'm not going to bother giving any personal advice or such on the emotional and physically demanding standpoint. (Though the advice she has received has been very honest, and meant in a kind and caring way, to warn her and help prepared her) No matter our age, our bodies and hormones are always going through changes. Usually these changes are not so dramatic that they are incredibly noticeable. But our periods do get thrown out of wack at times(for seemingly no apparent reason), and cause confusion and concern on our part. Therefore,7 days isn't incredibly late. You could be pregnant, but you could just be late, or even completely missed your period for this month.(I once went 2 months without a period, then started up again just like clockwork.) Basically all symptoms of pregnancy, are also the symptoms of an oncoming period, and therefore really can't be used as a guide. (and as far as I know, having errect nipples isn't a sign of pregnancy.also, USUALLY this early in a pregnancy, you won't be out growing your clothes, especially if its your first. It is possible, but not usually. It sounds as though it is bloating, possibly from your upcoming period?) As you are one week late, you can take an hpt. You can also try to get a blood test done. These are more accurate then hpts.Should you get a positive, set up a prenatal appointment, and start taking prenatal vitamins. Should you miss your next period, yet get negatives on your tests, definitely go see your doctor. You could be pregnant and your hcg levels just not high enough to show on a test yet, OR there could be something else causing your irregular period. I hope that your life turns out as picture perfect as you envision. Good luck and best wishes.