FicWad

Oh honey, how old are you?
Cause my body did tricks like that my entire teenage years.. So it may very well be just your body reacting to something - stress, weight loss, lack of sleep, anything really..

But of course it's the best to check instead of waiting around, convincing yourself it's nothing.
I take it, since you think pregnancy is a possibility, that you've been with someone without protection, so if I were you and couldn't afford a test (btw they're more expensive in pharmacies, grocery stores sell reliable tests for a few bucks) I would propably count the days real closely first. From the day you've had sex to the day your period should've started and to this date on which you're late how much, two weeks?
You can find information on the internet, and it's pretty easy to count if pregnancy REALLY is an option. Most don't know it, or believe it, but the way our bodies work the chances are sometimes quite slim.

Anyway, been there done that that's what all this babbling comes from :)
Try to buy a test as soon as you can and maybe tell some adult that you trust about the situation, if you feel like that's something you feel good about doing.

you can always email me at obvious-@hotmail.com incase you feel like it :)