Yes a 9 speed will have 8 clicks.
Do as Zachariah says and use the cable adjuster to slacken the cable, or disconnect the RD cable entirely and work the shifter while gently tensioning the wire with your other hand. If it still only has 7 clicks either there's something wrong in the lever, or possibly the cable head isn't seated properly in the lever limiting it's motion.
If it has 8 clicks before connecting, pedal the bike to let the RD shift to high gear, and connect the wire while the lever is in the high gear position pulling up all the slack. Now , while pedaling, shift one click and use the cable adjuster to tension the cable so the RD makes the corresponding shift. This is the approximate cable adjustment, fine tune the trim for optimum shifting.