Confused

Well, they phoned from the clinic with a negative result. But was also a bit surprised that I came to do the test even though I'm not late getting my period and told me to come and have the test done again if I don't get my period by Sunday. I really don't know what to think. If the blood I saw was indeed implantation blood (and I really can't see any reason why not - I am basically a very healthy person, and it seems too much of a coincidence that at this very specific moment in my life it should indicate some ill with me) and if it appeared a week ago, then surly by now a blood test would be able to say that I'm pregnant. So.. maybe there was a beginning of an implantation, but somehow it didn't work out (the story I will stick to if indeed I've failed this cycle!).
And I'm so confused. I thought that two weeks since insemination was enough. That I don't have to wait for my period to show up (or rather not show..), but that I could come and have a test done. So should I be sad, or could I be hopeful? Is a "no" after two weeks a definite no, or maybe if my periods are a bit longer than usual I should give myself an extra day or two? It's funny, although I am definitely upset (and very moody), I don't know if to laugh or cry, if it's good news or bad news.

Anyway, in the action front I have a few possibilities:

1. Wait till Sunday. If I don't get a period by then, go and have a blood test again on Monday morning.
2. Like pervious clause, but before do a home pregnancy test (first would have to overcome my embarassy of buying such a thing..), and only if there is some kind of indication of a positive result go ahead and do the blood test.
3. Wait another week and see what happens. I should be getting my period from about Monday-Wednesday. If (if!) I don't get it by Wednesday, then I could surly assume pregnangcy and take the test again.