We had been TTC for a year, and with irregular cycles, I had no idea I was pregnant. I thought AF was coming due to cramping, so I took an HPT and was shocked that it came back +. I took several more that day, and another almost every day for quite some time (I was paranoid that something would go wrong).
I actually kept most of the tests in a ziploc, and took pictures of all of them. I just recently threw the tests away, as the digitals no longer read + and the lines on the others had faded to non-existent.