Did any of you experience this and then find out you were pregnant?

Ok, last month i started my period on the 21st and by the 24th i only had spotting. it was shorter than normal ( my periods last 6-8 days) and lighter than normal with no cramping like i usually get. I took a test around the 4th of June and it was negative. Now i'm waiting on my period ( i can go 29-32 days) but on day 29 i had cramping like i was going to start my period and it didnt show, i had some cramping yesterday in the morning but that was it. now i feel pretty normal on day 31. I am also having a problem with tapioca pudding Friday i had one and it was fine but now they taste like pepto bismol, but only to me ( i've had others try it)... Have any of you experienced something like this only to find out you were pregnant? Dose it sound like i should spend the money on a test or just wait it out a little longer?