Stressed out

So my period was supposed to come today but still hasn't i took a test and it was very faint ( my older sister said she couldn't tell ). With my first child i was only 15 when i found out and the tests i took was positive with in a few seconds and was a very bright blue positive. I have a chance of being pregnant, but not really sure what to do right now, i think i should wait and take another test in a few days but im like kinda freaking out.