It is a waiting game. Wait until ur period have delay by a week and start taking pregnancy test kits to see if it’s positive. Even if it’s negative, it’s also probably might be ur hcg levels are not high yet. And then, u need to wait a few more days or even week and test again.
You can't tell until you've missed your period, that's for certain. Pregnancy & period symptoms are almost the same so you can only know and check once you've missed a period. Best is 7 days after. That's when the line will be darker if you're pregnant.