I think you tested too early. Usually, it is best to wait and test when your period is officially late. Some early results tests can give positive results up to 5 days before your period--though the box cheats a little with the 5th day being the day you expect your period. Still, only about 30% pregnant of women will have a positive result 4 days before their period. The percentage goes up the closer you get to your expected period.

You could be pregnant, but PMS symptoms can also mimic early pregnancy symptoms. Especially if you are hoping to be pregnant, you may notice every little possible sign your body could produce of early pregnancy.

Some women get early symptoms, but let me tell you, I did not have any. In fact, I was 100% sure I would start my period when I got the positive on the test. I did have period like cramping around the time I believe implantation occurred (6 DPO), but it only lasted 1 day then went away. After I got my positive though, I did have period-like cramps for a couple of weeks.

Wait until your period is late and test again.

Good luck!