Hello, And Thanks For Your Hard Work. I Took Postinor

Hello, and thanks for your hard work.
I took postinor 2 about 5 weeks ago, I had "my period" (which I guess was caused by postinor) for 5 days.

My period was due on Monday but it hasn't come, I made a pregnancy test on Tuesday and it came out negative, but I am really worried since I am getting all the menstrual symptoms but no bleeding.
Could I be pregnant?...
* I am also very irregular.
Thanks.