My doctor says that HPTs can bevery good at telling you you're pregnant but not very good at telling you you're not, if you know what I mean.

I received two negative HPTs (and I used the special early tester kind) and this was when my period was actually due. As I was on IVF, I was having a blood test anyway and this picked up the pregnancy. If you are in any doubt and your period is still absent, go the blood test.