I took a test again this morning and again got a negative result. And yes my periods were completely normal after I got off of the pill. I haven't ever had any problems with my period even before I started the pill I would only be a day or two late at the most and that was a rare occurence in itself.
If you got pregnant on the 18th or shortly before, it would likely be a bit too early to get a positive result on an HPT. Test again in a week, if it still hasn't come. If that comes back negative, I'd talk to your doctor--especially since, if I understand correctly, your periods were normal after getting off the pill up until this time around?