when to test

I had a 33 day cycle last month. The first day of this cycle was October 1. I believe I ovulated on the 20th. I had some kind of brown discharge on the 23. I wouldn't have known if I hadn't been checking inside and not just with toliet tissue. I took an test (regular one/not a early test) in mid day today that gave me an negitive. Should I go by this or should I wait until the end of the week and test first thing in the morning? I really do feel like I'm having early pregnancy signs, I have had three children so far.