I have a 97' olds 88 what could be wrong? <continued>?

I changed the fuel pump and put it all back together, hooked the battery charger up to it, turned the key to run the fuel pump a couple times, and when I went to start it, it just clicked..so I got out moved the negative cable a little bit to make sure it was sparking, went back and it rolled over and started..called it a day. Then the next day went to start it to pull it out of the garage, hooked the battery charger up to it again and it just clicked..I went and grabbed the battery tester and the battery is good, and the connections are clean and tight..Dont know why it won't turn over now.