Pregnancy and period. For the same.

There was a delay in periods. The blood was coming little bit for like few times but it's doesn't feels like period. Also there are little symptoms of periods but periods is not coming. Is there chances of pregnancy. I have done pregnancy test yesterday but result comes negative. There is almost all symptoms of periods but is not coming and also symptoms of pregnancy is not that much. That period date has passed and don't know whether it's coming or something else is there. It's feels like period but no period. Can you please tell the possible reasons for this and is there chances of pregnancy. If yes then should I again take the test and which time will be best for the good and accurate results. And also is period is not coming then how to bring it and what could be the all possible reasons for the same.